In this paper, the ability of chitosan film to remove dyestuff from wastewater was evaluated for environmental applications, using three commercial direct azo dyes. Two chitosan films were adopted: the standard one prepared following a well-known procedure to form it, and a novel one, with a weakly acidic character. Moreover, to improve the adsorption process, the hydrophobic character of the films was investigated. The pH of the dye solutions was also changed, showing an excellent ability in dye removal at pH 12. The films were characterized by means of spectroscopic and morphologic methods to better understand the nature of interactions between dyes and chitosan chains. Swelling ratio measurements were also performed. All analyses suggest that all dyes showed a strong affinity to chitosan polymer chains, with the presence of extended hydrogen bonds and Van der Waals forces perturbing the chitosan network. Interestingly, very good results were obtained in recycling experiments related to the dyeing capacities of chitosan blended films in the presence of textiles. An ecofriendly application is thus presented in this paper.

The paper reveals a dual-band electrochromic device capable of selectively controlling the transmitted sunlight in the visible and near-infrared regions. It exploits the peculiar spectro-electrochemical features of vanadium-modified titanium oxide colloidal nanocrystals, which exhibit a distinctive electrochromic response at visible wavelengths upon the application of a small cathodic potential. They have been used as an active electrode in a sandwich cell in combination with a nanocrystalline tungsten oxide layer, which indeed allows selective control over the incoming near-infrared radiation at low applied potentials, until turning into a deep blue colored coating at higher potentials. These two coatings have been conveniently combined to realize an electrochromic device capable of separately operating over four different optical regimes, namely, fully transparent, VIS blocking, NIR blocking, and VIS + NIR blocking. Great benefits are anticipated in the field of glazing elements for buildings and transportation, where the solution proposed here may pave the way for the implementation of a novel class of "zero-energy" smart windows that self-adapt to both external climatic conditions and interior visual and thermal comfort requirements.

The properties of nanoscale materials vary with the size and shape of the building blocks, which can be measured by (grazing-incidence) small-angle X-ray scattering along with the mutual positions of the nanoparticles. The accuracy in the determination of such parameters is dependent on the signal-to-noise ratio of the X-ray scattering pattern and on the visibility of the interference fringes. Here, a first-generation-synchrotron-class X-ray laboratory microsource was used in combination with a new restoration algorithm to probe nanoscale-assembled superstructures. The proposed algorithm, based on a maximum likelihood approach, allows one to deconvolve the beam-divergence effects from data and to restore, at least partially, missing data cut away by the beam stopper. It is shown that the combination of a superbright X-ray laboratory microsource with the data-restoring method allows a virtual enhancement of the instrument brilliance, improving signal-to-noise ratio and fringe visibility and reaching levels of performance comparable to third-generation synchrotron radiation beamlines.

N-functionalization of 5,6-dihydroxyindole with a hydrophilic triethyleneglycol (TEG) chain provides access to a new class of water-soluble eumelanin-like materials with relatively high dielectric constant and polyelectrolyte behaviour, reflecting enhanced charge transport by in-depth incorporation of hydration networks.

Nucleophosmin (NPM1) is the most frequently mutated gene in Acute Myeloid Leukemia (AML) patients and mutations lead to its aberrant cytoplasmatic accumulation in leukemic cells. Its C-terminal domain (CTD) is endowed with a globular structure consisting of a three-helix bundle in the wild type form that is disrupted by AML mutations. Our recent results demonstrate, unexpectedly and unequivocally, that regions of the CTD of NPM1 are prone to aggregate to amyloid states. Here we present novel studies, at solution as well as fibrillar states of a nonapeptide covering the 264-272 region of NPM1: this small fragment is the most amyloidogenic stretch of the entire protein and its conformational and aggregation properties were investigated through Circular Dichroism, Fluorescence spectroscopies, amyloid seeding assay (ASA), isothermal titration calorimetry (ITC) and electrospray ionization (ESI) mass analyses. Structural features of fibrils were investigated by means of Scanning Electron Microscopy (SEM) and Wide-Angle X-ray Scattering (WAXS). This study deepens the amyloid fibrillization process of a short stretch of the CTD likely involved in the propagative mechanism for NPMc+ cytoplasmatic accumulation in leukemogenesis.

Phenylalanine-based nanostructures have attracted the attention of the material science community for their functional properties. These properties strongly depend on the hierarchic organization of the nanostructure that in turn can be finely tuned by punctual chemical modifications of the building blocks. Herein, we investigate how the partial or the complete replacement of the Phe residues in PEG(8)-(Phe)(6) (PEG(8)-F-6) with tyrosines to generate PEG(8)-(Phe-Tyr)(3) (PEG(8)-(FY)3) or PEG(8)-(Tyr)(6) (PEG(8)-Y6) affects the structural/functional properties of the nanomaterial formed by the parental compound. Moreover, the effect of the PEG derivatization was evaluated through the characterization of the peptides without the PEG moiety (Tyr)(6) (Y6) and (Phe-Tyr)(3) ((FY)3). Both PEG(8)-Y6 and PEG(8)-(FY)3 can self-assemble in water at micromolar concentrations in beta-sheet-rich nano structures. However, WAXS diffraction patterns of these compounds present significant differences. PEG(8)-(FY)3 shows a 2D WAXS oriented fiber diffraction profile characterized by the concomitant presence of a 4.7 angstrom meridional and a 12.5 angstrom equatorial reflection that are generally associated with cross-beta structure. On the other hand, the pattern of PEG(8)-Y6 is characterized by the presence of circles typically observed in the presence of PEG crystallization. Molecular modeling and dynamics provide an atomic structural model of the peptide spine of these compounds that is in good agreement with WAXS experimental data. Gelation phenomenon was only detected for PEG(8)-(FY)3 above a concentration of 1.0 wt% as confirmed by storage (G' approximate to 100 Pa) and loss (G '' approximate to 28 Pa) moduli in rheological studies. The cell viability on CHO cells of this soft hydrogel was certified to be 90% after 24 hours of incubation.

The paper shows how a table top superbright microfocus laboratory X-ray source and an innovative restoring-data algorithm, used in combination, allow to analyze the super molecular structure of soft matter by means of Small Angle X-ray Scattering ex-situ experiments. The proposed theoretical approach is aimed to restore diffraction features from SAXS profiles collected from low scattering biomaterials or soft tissues, and therefore to deal with extremely noisy diffraction SAXS profiles/maps. As biological test cases we inspected: i) residues of exosomes' drops from healthy epithelial colon cell line and colorectal cancer cells; ii) collagen/human elastin artificial scaffolds developed for vascular tissue engineering applications; iii) apoferritin protein in solution. Our results show how this combination can provide morphological/structural nanoscale information to characterize new artificial biomaterials and/or to get insight into the transition between healthy and pathological tissues during the progression of a disease, or to morphologically characterize nanoscale proteins, based on SAXS data collected in a room-sized laboratory.

The coupling and propagation of electromagnetic waves through planar X-ray waveguides (WG) with vacuum gap and Si claddings are analyzed in detail, starting from the source and ending at the detector. The general case of linearly tapered WGs (i.e. with the entrance aperture different from the exit one) is considered. Different kinds of sources, i.e. synchrotron radiation and laboratory desk-top sources, have been considered, with the former providing a fully coherent incoming beam and the latter partially coherent beams. It is demonstrated that useful information about the parameters of the WG can be derived, comparing experimental results with computer simulation based on analytical solutions of the Helmholtz equation which take into account the amplitude and phase matching between the standing waves created in front of the WG, and the resonance modes propagating into the WG

Conjugated polymers are complex multichromophore systems, with emission properties strongly dependent on the electronic energy transfer through active subunits. Although the packing of the conjugated chains in the solid state is known to be a key factor to tailor the electronic energy transfer and the resulting optical properties, most of the current solution-based processing methods do not allow for effectively controlling the molecular order, thus making the full unveiling of energy transfer mechanisms very complex. Here we report on conjugated polymer fibers with tailored internal molecular order, leading to a significant enhancement of the emission quantum yield. Steady state and femtosecond time-resolved polarized spectroscopies evidence that excitation is directed toward those chromophores oriented along the fiber axis, on a typical time scale of picoseconds. These aligned and more extended chromophores, resulting from the high stretching rate and electric field applied during the fiber spinning process, lead to improved emission properties. Conjugated polymer fibers are relevant to develop optoelectronic plastic devices with enhanced and anisotropic properties.

Biofilm formation is one of the main obstacles that occur during in vivo implantation, which compromises the implant functionality and patients' health. This is the inspiration for the development of novel implant materials that contain broad-spectrum antimicrobial activity, including antibacterial and antifungal, and enable the local release of antimicrobial agents. Here, multifunctional calcium phosphate-ionic liquid (IL) materials, possessing antimicrobial and repair/regeneration features plus injectability, are proposed as implants in minimally invasive surgery. This approach was based on the loading of 1-alkyl-3-alkylimidazolium chloride ionic liquids (ILs) (CnMImCl (n = 4, 10, 16) and (C10)2MImCl) during the in situ sol-gel synthesis of calcium phosphates (CaP) and study of their effects on CaP crystallization and biological properties. Physical, morphological, and biological investigations were performed to evaluate the bionanocomposites' properties. The IL N-alkyl chain length influenced the crystallization of CaP and, consequently, the biological properties, which afforded bionanocomposites (when loaded with C16MImCl or (C10)2MImCl) that, (i) inhibit both in vitro bacterial and fungal growth; (ii) reduce the in vitro inflammatory response; (iii) induce osteogenic differentiation in the basal medium of human mesenchymal stem cells; and (iv) are injectable. This will enable the design of multifunctional injectable implants with antimicrobial, anti-inflammatory, and regenerative properties to be used in minimally invasive surgery of bone and maxillofacial defects.

A colloidal nonaqueous approach to semiconductor-magnetic hybrid nanocrystals (HNCs) withselectable heterodimer topologies and tunable geometric parameters is demonstrated. Brookite TiO2nanorods, distinguished by a curved shape-tapered profile with richly faceted terminations, are exploitedas substrate seeds onto which a single spherical domain of inverse spinel iron oxide can be epitaxiallygrown at either one apex or any location along their longitudinal sidewalls in a hot surfactant environment.The topologically controlled arrangement of the component material lattices, the crystallographic relationshipsholding between them, and strain distribution across individual heterostructures have been studied bycombining X-ray diffraction and absorption techniques with high-resolution transmission electron microscopyinvestigations. Supported by such structural knowledge, the synthetic achievements are interpreted withinthe frame of various mechanistic models offering complementary views of HNC formation. The differentHNC architectures are concluded to be almost equivalent in terms of surface-interface energy balanceassociated with their formation. HNC topology selection is rationalized on the basis of a diffusion-limitedmechanism allowing iron oxide heterogeneous nucleation and growth on the TiO2 nanorods to switch froma thermodynamically controlled to a kinetically overdriven deposition regime, in which the anisotropicreactivity offered by the uniquely structured seeds is accentuated under high spatially inhomogeneousmonomer fluxes. Finally, the multifunctional capabilities of the heterostructures are highlighted throughillustration of their magnetic and photocatalytic properties, which have been found to diverge from thoseotherwise exhibited by their individual material components and physical mixture counterparts.

The ability of peptides to self-assemble represents a valuable tool for the development of biomaterialsof biotechnological and/or biomedical interest. Diphenylalanine homodimer (FF) and its analogues areamong the most promising systems in this field. The longest Phe-based building block hithertocharacterized is pentaphenylalanine (F5). We studied the aggregation propensity and the structural/morphological features of assemblies of zwitterionic hexaphenylalanine H+-F6-O and of three variantscharacterized by different charged states of the terminal ends (Ac-F6-Amide, H+-F6-Amide and Ac-F6-O).As previously observed for PEGylated hexaphenylalanine (PEG8-F6), all F6 variants show a strong tendencyto form b-rich assemblies in which the structural motif is constituted by antiparallel b-strands in thecross-b framework. Extensive replica exchange molecular dynamics simulations carried out on a pairs ofF6 peptides indicate that the antiparallel b-structure of the final assemblies is likely dictated by thepreferred association modes of the individual chains in the very early stages of the aggregation process.Our data suggest that even very small F6 peptides are properly pre-organized and prone to the build-upof the final assembly.

In this chapter, we will focus on a specific X-ray-based technique among those employed in surface science and which is especially suitable for the study of self-assembled nanocrystals: Grazing Incidence Small Angle X-ray Scattering (GISAXS). We will first introduce the main field of investigation considered herein, with basic notions of X-ray scattering from surfaces, and then address basic concepts about GISAXS. Finally, we will describe a few relevant examples of studies, of nanostructured architectures, through ex situ and in situ experiments of grazing incidence X-ray scattering. This manuscript is focused on the former, showing that they can be performed by using laboratory instruments. In situ investigations still need synchrotron radiation sources in most cases; therefore, only a few examples selected from the literature are reported here, for the sake of completeness. The experiments described are mainly performed in the small angle range, providing information on the size and shape of nanocrystals, together with their spatial arrangement. Both 2D and 3D architectures are considered. In particular, GISAXS measurements of 2D superlattices of nano-octapods, performed both at a third generation synchrotron beamline and with a table-top set-up, are compared; the employed table-top set-up is described in a dedicated paragraph. Further examples of grazing incidence studies as performed by the authors with a table-top set-up are reported: a GISAXS study of 3D iron oxide nanocrystal superlattices, showing the importance of modelling in order to obtain structural information from data; a combined small/wide angle scattering (GISAXS/GIWAXS) study of 3D PbS nanocrystal superlattices; and a GIWAXS study of P3HT nanofibres, showing how the ordering at the molecular and atomic length scales can be obtained by exploring different angular ranges in the same grazing incidence geometry. Finally, selected examples of in situ GISAXS studies, performed with synchrotron radiation sources, are described.

Arranging anisotropic nanoparticles into ordered assemblies remains a challenging quest requiring innovative andingenuous approaches. The variety of interactions present in colloidal solutions of nonspherical inorganic nanocrystals can be exploited for this purpose. By tuning depletion attraction forces between hydrophobic colloidal nanorods of semiconductors, dispersed in an organic solvent, these could be assembled into 2D monolayers of close-packed hexagonally ordered arrays directly in solution. Once formed, these layers could be fished onto a substrate, and sheets of vertically standing rods were fabricated, with no additional external bias applied. Alternatively, the assemblies could be isolated and redispersed in polar solvents, yielding suspensions of micrometer- sized sheets which could be chemically treated directly in solution. Depletion attraction forces were also effective in the shape-selective separation of nanorods from binary mixtures of rods and spheres. The reported procedures have the potential to enable powerfuland cost-effective fabrication approaches to materials and devices based on self-organized anisotropic nanoparticles.

We performed reproducible atomic resolution Transmission Electron Microscopy and Wide Angle X-ray Scanning Microscopy experiments studying for the first time the nanoscale properties of a pristine fiber taken from the Turin Shroud. We found evidence of biologic nanoparticles of creatinine bounded with small nanoparticles of iron oxide. The kind, size and distribution of the iron oxide nanoparticles cannot be dye for painting but are ferrihydrate cores of ferritin. The consistent bound of ferritin iron to creatinine occurs in human organism in case of a severe polytrauma. Our results point out that at the nanoscale a scenario of violence is recorded in the funeral fabric and suggest an explanation for some contradictory results so far published.

The challenge of fine compositional tuning and microstructure control in complex oxides is overcome by developing a general two-step synthetic approach. Antimony-alloyed bismuth vanadate, which is identified as a novel light absorber for solar fuel applications, is prepared in a wide compositional range. The bandgap of this quaternary oxide linearly decreases with the Sb content, in agreement with first-principles calculations.

Inorganic nanocrystals (NCs) based nanovectors offer the potential for new and innovative drug delivery systems for a targeted transport of drugs towards tissues affected by most aggressive disease including cancer. Diagnostic and therapeutic applications require, for both in-vitro and in-vivo investigation, the determination of the maximum cellular dose of these nanovectors [1] that is also mandatory for any regulatory approval [2]. Accurate determination of the nanovector concentration is not a trivial issue and currently there is a lack of experimental methods recognized as general and reliable [3]. In this work, we propose an approach for the determination of the concentration of a solid lipid nanoparticle (SLN) nanovector encapsulating photoactive copper sulfide (Cu2-xS) NCs characterized by a tunable localized surface plasmon resonance (LSPR) in the biological transparent near-infrared (NIR) spectral region for photothermal therapy. Here, Cu2-xS NCs with a narrow size distribution and an intense LSPR in the second biological window have been synthesized by hot injection method and they have been encapsulated into SLN prepared by a hot homogenization technique using a mixture of lipids, triglycerides and phospholipids. A calculation method based on Mie-Drude theory using as input data resulting from spectroscopic and dimensional investigation for the Cu2-xS NCs and NCs containing SLNs has been successfully implemented and applied for the determination of the nanovector concentration. The results are in agreement with experimental data and the proposed approach hold a great potential for determining the concentration of plasmonic NCs based nanovectors.

The development of green and scalable syntheses for the preparation of size- A nd shape-controlled metal nanocrystals is of high interest in many areas, including catalysis, electrocatalysis, nanomedicine, and electronics. In this work, a new synthetic approach based on the synergistic action of physical parameters and reagents produces size-tunable octahedral Pt nanocrystals, without the use of catalyst-poisoning reagents and/or difficult-to-remove coatings. The synthesis requires sodium citrate, ascorbic acid, and fine control of the reduction rate in aqueous environment. Pt octahedral nanocrystals with particle size as low as 7 nm and highly developed {111} facets have been achieved, as demonstrated by transmission electron microscopy, X-ray diffraction, and electrochemical methods. The absence of sticky molecules together with the high quality of the surface makes these nanocrystals ideal candidates in electrocatalysis. Notably, 7 nm bismuth-decorated octahedral nanocrystals exhibit superior performance for the electrooxidation of formic acid in terms of both specific and mass activities.

Here we describe a new TEM-based coherent diffraction imaging (CDI) method to achieve sub-ångström resolution in lattice images of nanoparticles. The experiments were performed by using a TEM/STEM JEOL 2010F UHR (objective lens spherical aberration coefficient of (0.47±0.01) mm) with resolution at optimum defocus of 0.19nm and equipped by Schottky cathode. The experiments for CDI require the acquisition of HRTEM image and diffraction from the same region of the sample illuminated by a coherent electron probe. The experimental nano-diffraction must be recorded with the beam coherence length larger than the region to be imaged according to the oversampling requirements [1]. A new efficient iterative phase retrieval algorithm [2] based on pioneering work of Gerchberg and Saxton [3] has been developed and successfully applied. Figure 1 is an example of phase retrieval of a TiO2 particle at a resolution of 70 pm that allows to distinguish the O atoms appreciating subtle alterations in the unit cell structure of the nano-crystals, which would not be otherwise detectable by conventional HRTEM. Such structural deviations could be at the origin of peculiar size-dependent physical-chemical properties of the concerned oxide material in the nanoscale regime [2].

The paper focuses on the development of electron coherent diffraction imaging intransmission electron microscopy, made in the, approximately, last ten years in our collaborativeresearch group, to study the properties of materials at atomic resolution, overcoming the limitationsdue to the aberrations of the electron lenses and obtaining atomic resolution images, in whichthe distribution of the maxima is directly related to the specimen atomic potentials projected ontothe microscope image detector. Here, it is shown how augmented coherent diffraction imagingmakes it possible to achieve quantitative atomic resolution maps of the specimen atomic species,even in the presence of low atomic number atoms within a crystal matrix containing heavy atoms.This aim is achieved by: (i) tailoring the experimental set-up, (ii) improving the experimental data byproperly treating parasitic diffused intensities to maximize the measure of the significant information,(iii) developing efficient methods to merge the information acquired in both direct and reciprocalspaces, (iv) treating the dynamical diffused intensities to accurately measure the specimen projectedpotentials, (v) improving the phase retrieval algorithms to better explore the space of solutions.Finally, some of the future perspectives of coherent diffraction imaging in a transmission electronmicroscope are given.

Suitable postsynthesis surface modification of lead-chalcogenide quantum dots (QDs) is crucial to enable their integration in photovoltaic devices. Here we exploit arenethiolate anions to completely replace pristine oleate ligands on PbS QDs in the solution phase, thus preserving the colloidal stability of QDs and allowing their solution-based processability into photoconductive thin films. Complete QD surface modification relies on the stronger acidic character of arenethiols compared to that of alkanethiols and is demonstrated by FTIR and UVvisNIR absorption spectroscopy analyses, which provide quantitative evaluation of stoichiometry and thermodynamic stability of the resulting system. Arenethiolate ligands induce a noticeable reduction of the optical band gap of PbS QDs, which is described and explained by charge transfer interactions occurring at the organic/inorganic interface that relax exciton confinement, and a large increase of QD molar absorption coefficient, achieved through the conjugated moiety of the replacing ligands. In addition, surface modification in the solution phase promotes switching of the symmetry of PbS QD self-assembled superlattices from hexagonal to cubic close packing, which is accompanied by further reduction of the optical band gap, ascribed to inter-QD exciton delocalization and dielectric effects, together with a drastic improvement of the charge transport properties in PbS QD solids. As a result, smooth dense-packed thin films of arenethiolate-capped PbS QDs can be integrated in heterojunction solar cells via a single solution-processing step. Such single PbS QD layers exhibit abated cracking upon thermal or chemical postdeposition treatment, and the corresponding devices generate remarkable photocurrent densities and overall efficiencies, thus representing an effective strategy toward low-cost processing for QD-based photovoltaics.

We report a low-temperature colloidal synthesis of single-layer, five-atom-thick, beta-In2Se3 nanosheets with lateral sizes tunable from 300 to 900 nm, using short aminonitriles (dicyandiamide or cyanamide) as shape controlling agents. The phase and the monolayer nature of the nanosheets were ascertained by analyzing the intensity ratio between two diffraction peaks from two-dimensional slabs of the various phases, determined by diffraction simulations. These findings were further backed-up by comparing and fitting the experimental X-ray diffraction pattern with Debye formula simulated patterns and with side-view high-resolution transmission electron microscopy imaging and simulation. The beta-In2Se3 nanosheets were found to be indirect band gap semiconductors (Eg = 1.55 eV), and single nanosheet photodetectors demonstrated high photoresponsivity and fast response times.

Colloidal PbTe nanocrystals are reacted with AuCl3 in the presence of dodecylamine and tetraoctylammonium bromide in a toluene solution. At room temperature, only homogenous nucleation of isolated Au nanocrystals in solution is observed. At higher temperatures (i.e. 60 °C or higher) the gold ions/atoms are able to diffuse through the PbTe nanocrystals and to form one or more metallic gold regions inside them, while most of the remaining volume of each nanocrystal becomes amorphous. Longer reaction times lead to the growth of a single balloon-shaped Au domain attached via its apex to the surface of each nanocrystal. The structural and compositional quantification of the starting PbTe nanocrystals and of the various reaction products is often complicated by several reactive processes occurring during in situ analysis by electron microscopy. Evidences of the formation of a metastable Au3Te compound are presented. © 2010 The Royal Society of Chemistry.

We present the synthesis of polymer embedded colloidal ordered assemblies, built from highly ordered superparamagnetic manganese iron oxide nanocrystals. Each assembly is wrapped into a thin polymer shell. In-depth characterization of the nanoparticles by TEM, SAXS, SQUID, and magnetophoresis indicates that these colloidal hybrids exhibit high mobilities in external magnetic fields, and that they could efficiently serve as contrast enhancers in magnetic resonance imaging.

Excitation of lattice vibrations in nanostructured anatase TiO2 frequently occurs at energy values differingfrom that found for the corresponding bulk phase. Particularly, investigations have long aimed at establishinga correlation between the low-frequency Eg(1) mode and the mean crystallite size on the basis of phononconfinementmodels. Here, we report a detailed Raman study, supported by X-ray diffraction analyses, onanatase TiO2 nanocrystals with rod-shaped morphology and variable geometric parameters, prepared by colloidalwet-chemical routes. By examining the anomalous shifts of the Eg(1) mode in the spectra of surfactantcappednanorods and in those of corresponding organic-free derivatives (obtained by a suitable thermal oxidativetreatment), an insight into the impact of exposed facets and of the coherent crystalline domain size onRaman-active lattice vibrational modes has been gained. Our investigation offers a ground for clarifying thecurrent lack of consensus as to the applicability of phonon-confinement models for drawing information on thesize of surface-functionalized TiO2 nanocrystals upon analysis of their Raman features.

The evolution from solvated precursors to hybrid halide perovskite films dictates most of the photophysicaland optoelectronic properties of the final polycrystalline material. Specifically, the complex equilibria andthe importantly different solubilities of lead iodide (PbI2) and methylammonium iodide (MAI) induceinhomogeneous crystal growth, often leading to a defect dense film showing non-optimaloptoelectronic properties and intrinsic instability. Here, we explore a supramolecular approach based onthe use of cyclodextrins (CDs) to modify the underlying solution chemistry. The peculiar phenomenondemonstrated is a tunable complexation between different CDs and MA+ cations concurrent to an out ofcage PbI2 intercalation. Notably, the first report of a connection between the solvation equilibria of thetwo perovskite precursors identified the optimal conditions in terms of CD cavity size and polarity andthose translate to a neat enhancement of PbI2 solubility in the reaction media, leading to an equilibration3 of the availability of the precursors in solution. The macroscopic result of this is an improved nucleationprocess, leading to a perovskite material with higher crystallinity, better optical properties and improvedmoisture resistance. Remarkably, the use of CDs presents a great potential for a wide range of devicerelatedapplications, as well as for the development of tailored composite materials.

In this study we evaluated an efficient microwave-solvothermal method to synthesize effective visible-light photocatalists based on the use of anatase TiO2 nanorods. The nanocrystals were obtained by hydrolysis of titanium tetraisopropoxide (TTIP) in the presence of benzyl alcohol at 210 C. The method was effective and produced TiO2 nanocrystals in the anatase phase with a rapid kinetics of crystallization. A significant size control was obtained tuning the TTIP to oleic acid molar ratio. High volumetric yield and reduced energy costs were achieved. All synthesized TiO2 nanocrystals showed a high photoactivity in comparison with commercial P25 titania, as they could degrade faster and completely Rhodamine B dye in solution under visible-light irradiation. The nanocrystals were characterized in detail by X-ray diffraction, low- and high-resolution transmission electron microscopy, microRaman and FT-IR spectroscopy. A distorted anatase structure due to oxygen vacancies was identified as being at the origin of the introduction of new energy levels into the anatase band gap, which probably promoted the visible-light photoactivity.

Scanning small and wide angle X-ray scattering (scanning SWAXS) experiments were performed on healthy and pathologic human bone sections. Via crystallographic tools the data were transformed into quantitative images and as such compared with circularly polarized light (CPL) microscopy images. SWAXS and CPL images allowed extracting information of the mineral nanocrystalline phase embedded, with and without preferred orientation, in the collagen fibrils, mapping local changes at sub-osteon resolution. This favorable combination has been applied for the first time to biopsies of dwarfism syndrome and Paget's disease to shed light onto the cortical structure of natural bone in healthy and pathologic sections.

Very recently we proposed novel di- and tetra-phenylalanine peptides derivatized with gadolinium complexes as potentials supramolecular diagnostic agents for applications in MRI (Magnetic Resonance Imaging). It was observed that in very short FF dipeptide building blocks, the propensity to aggregate decreases significantly after modification with bulky moiety such as Gd-complexes, thus limiting their potential as CAs. We hypothesized that the replacement of the Phe side chain with more extended aromatic groups could improve the self-assembling. Here we describe the synthesis, structural and relaxometric behavior of a novel water soluble self-assembled peptide CA based on 2-naphthylalanine (2Nal). The peptide conjugate Gd-DOTA-L-6-(2Nal)(2) is able to self-assemble in long fibrillary nanostructures in water solution (up to 1.0 mg/mL). CD and FTIR spectroscopies indicate a beta sheet secondary structure with an antiparallel orientation of single strands. All data are in good agreement with WAXS and SAXS characterizations that show the typical "cross-beta pattern" for fibrils at the solid state. Molecular modeling indicates the three-dimensional structure of the peptide spine of aggregates is essentially constituted by extended beta-sheet motifs stabilized by hydrogen bonds and hydrophobic interactions. The high relaxivity of nanoaggregates (12.3 mM(-1) s(-1) at 20 MHz) and their capability to encapsulate doxorubicin suggest their potential application as supramolecular theranostic agents.

DEBUSSY is a new free open-source package, written in Fortran95 and devoted to the application of the Debye function analysis (DFA) of powder diffraction data from nanocrystalline, defective and/or non-periodic materials through the use of sampled interatomic distance databases. The suite includes a main program, taking the name of the package, DEBUSSY, and dealing with the DFA of X-ray, neutron and electron experimental data, and a suite of 11 programs, named CLAUDE, enabling users to create their own databases for nanosized crystalline materials, starting from the list of space-group generators and the asymmetric unit content. A new implementation of the Debye formula is adopted in DEBUSSY, which makes the approach fast enough to deal with the pattern calculation of hundreds of nanocrystals, to sum up their contributions to the total pattern and to perform iterative algorithms for optimizing the parameters of the pattern model. The package strategy uses the sampled-distance database(s) created previously by CLAUDE and combines, for any phase, a log-normal or a bivariate log-normal function to deal with the sample-size distribution; four different functions are implemented to manage possible lattice expansions/contractions as a function of crystal size. A number of output ASCII files are produced to supply some statistics and data suitable for graphical use. The databases of sampled interatomic non-dimensional distances for cuboctahedral, decahedral and icosahedral structure types, suitable for dealing with noble metal nanoparticles, are also available.

The Debye Function Analysis of diffraction patterns from nanosized mineral crystals showing different average degrees of maturity was carried out on engineered bone samples. The analysis relied on a bivariate family of atomistic hydroxyapatite nanocrystal models and provided information about crystal structure, size and shape distributions of the mineral component of the newly formed bone. An average rod-like shape of nanocrystals was found in all samples, with average sizes well matching the collagen I gap region. The diffraction patterns investigated through the Debye Function Analysis were used as signal models to perform the Canonical Correlation Analysis of high resolution X-ray micro-diffraction patterns collected on porous and resorbable hydroxyapatite/silicon-stabilized tricalcium phosphate (Si-TCP) implants. The nosologic maps clearly showed a size gradient in the new formed bone that validates the mechanism (mimicking the bone remodelling in orthotopic bones) of a continuous deposition of bone by osteoblasts, an increasing mineralization of the newly deposited bone, a growth of the new crystals, at the same time that osteoclasts adhere to the scaffold surface and resorb the bioceramic. The comparison of samples at different implantation times proved that the selective resorption of Si-TCP component from the scaffold was already evident after two and almost complete after six months.

Purpose: In the hard x-ray region, the cross sections for the phase shift of low-Z elements are about 1000 times larger than the absorption ones. As a consequence, phase contrast is detectable even when absorption contrast is minimal or absent. Therefore, phase-contrast imaging could become a valid alternative to absorption contrast without delivering high dose to tissue/human body parts.

Herein, we demonstrate an EDI methodology, performed in a Jeol 2010F UHR microscope (spherical aberration coefficient Cs = 0.47±0.01 mm), by which the crystal structure of transition-metal oxide nanocrystals can be determined at 70 pm of resolution while unambiguously revealing the presence and location of light elements atomic columns in the relevant lattice. This approach, applied as a case study to TiO2 in the form of organic-capped nano-rods, also allows appreciating subtle alterations in the unit cell structure of the nano-crystals, relative to that inherent to the bulk material counterpart, which would not be otherwise detectable by conventional HRTEM. Such structural deviations could be at the origin of peculiar size-dependent physical-chemical properties of the concerned oxide material in the nanoscale regime. In addition, it is worthwhile to remark that this result has been achieved exposing the specimen to an electron dose as low as 106 e/nm2. The latter condition usually prevents the specimen against possible structural damages under exposure to 200 keV electrons, the induction of which remains one of the key issues in the ultimate accuracy achievable in the structural determination of materials [4].

We report a very effective synthetic approach to achieve the in situ growth, directly at the surface of single walled carbon nanotubes, of shape controlled anatase TiO2 nanocrystals, either as nanorods or nanospheres, by simply tuning the ratio between reactants. Remarkably, the obtained SWCNTs/TiO2 heterostructures result dispersible in organic solvents, leading to optically clear dispersions. The photocatalytic activity of the SWCNTs/TiO2 heterostructures, compared with bare TiO2 nanorods or nanospheres demonstrates a significant enhancement. In particular, SWCNTs/TiO2 heterostructures demonstrates an enhancement of reaction rate up to 3 times with respect to the commercially available standard TiO2 powder (TiO2 P25) under UV light and up to 2 times under visible light.

The specific routes of biomineralization in nature are here explored using a tissue engineering approach in which bone is formed in porous ceramic constructs seeded with bone marrow stromal cells and implanted in vivo. Unlike previous studies this model system reproduces mammalian bone formation, here investigated at high temporal resolution. Different mineralization stages were monitored at different distances from the scaffold interface so that their spatial analysis corresponded to temporal monitoring of the bone growth and mineralization processes. The micrometer spatial resolution achieved by our diffraction technique ensured highly accurate reconstruction of the different temporal mineralization steps and provided some hints to the challenging issue of the mineral deposit first formed at the organic-mineral interface. Our results indicated that in the first stage of biomineralization organic tissue provides bioavailable calcium and phosphate ions, ensuring a constant reservoir of amorphous calcium phosphate (ACP) during hydroxyapatite (HA) nanocrystal formation. In this regard we suggest a new role of ACP in HA formation, with a continuous organic-mineral transition assisted by a dynamic pool of ACP. After HA nanocrystals formed, the scaffold and collagen act as templates for nanocrystal arrangement on the microscopic and nanometric scales, respectively. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

ZnO thin films, prepared using a printing-compatible sol-gel method involving a thermal treatmentbelow 400 °C, are proposed as active layers in water-gated thin-film transistors (WG-TFTs). Thethin-film structure and surface morphology reveal the presence of contiguous ZnO crystalline(hexagonal wurtzite) with isotropic nano-grains as large as 10nm characterized by a preferentialorientation along the a-axis. The TFT devices are gated through a droplet of deionized waterby means of electrodes characterized by different work functions. The high capacitance ofthe electrolyte allowed operation below 0.5V. While the Ni, Pd, Au and Pt gate electrodes areelectrochemically stable in the inspected potential range, electrochemical activity is revealed for theW one. Such an occurrence leads to an increase of capacitance (and current), which is ascribed to ahigh output current from the dissolution of a lower capacitance W-oxide layer. The environmentalstability of the ZnO WG-TFTs is quite good over a period of five months

The aim of this work was to investigate the structural features of type I collagen isoforms and collagen-based films at atomic and molecular scales, in order to evaluate whether and to what extent different protocols of slurry synthesis may change the protein structure and the final properties of the developed scaffolds. Wide Angle X-ray Scattering data on raw materials demonstrated the preferential orientation of collagen molecules in equine tendon-derived collagens, while randomly oriented molecules were found in bovine skin collagens, together with a lower crystalline degree, analyzed by the assessment of FWHM (Full Width at Half Maximum), and a certain degree of salt contamination. WAXS and FT-IR (Fourier Transform Infrared) analyses on bovine collagen-based films, showed that mechanical homogenization of slurry in acidic solution was the treatment ensuring a high content of super-organization of collagen into triple helices and a high crystalline domain into the material. In vitro tests on rat Schwannoma cells showed that Schwann cell differentiation into myelinating cells was dependent on the specific collagen film being used, and was found to be stimulated in case of homogenization-treated samples. Finally DHT/EDC crosslinking treatment was shown to affect mechanical stiffness of films depending on collagen source and processing conditions.

Since its early days electron microscopy has represented a splendid way to study the interactions between charged particles and electromagnetic fields. These efforts produced a flexible and powerful tool to investigate the properties of the matter at the highest spatial resolution. One of the main reason for the high resolution achievable in electron microscopy is related to the small wavelength, l, associated to high-energy electrons, i.e. for 200 keV electrons l = 2.5pm. Unfortunately, the quality of the electron lenses is relatively poor and the diffraction limit is still unreached. The proof of Otto Scherzer in 1936 that skilful lens design could never eliminate the spherical and chromatic aberration of rotationally symmetric lenses [1] promote the efforts of the scientific community to find a gateway. Since that time many attempts were made from one side to find a way to correct spherical and chromatic aberrations via hardware and from the othe r to find different approaches to recovery the information lost in TEM imaging. In the latter approaches it might be mentioned, for example, the invention of Gabor of the holography [2] or the through focal reconstruction of the exit phase wave in high resolution TEM (HRTEM) [3]. Very recently, electron optical devices capable of correcting spherical aberration are available and sub-ångström resolution have been achieved by HRTEM [4] and incoherent imaging in scanning transmission electron microscopy (STEM) by using high angle annular dark field detector [5]. Nevertheless, the diffraction limit in electron microscopy is still not reached. Coherent diffraction imaging (CDI) is an approach combining real and reciprocal space information to achieve images in principle limited only by diffraction limit [6].

High-resolution imaging of low-atomic-number chemical elements using electron microscopy is challenging and may require the use of high doses of electrons. Electron diffractive imaging, which creates real-space images using diffraction intensities and phase retrieval methods, could overcome such issues, although it is also subject to limitations. Here, we show that a combination of electron diffractive imaging and high-resolution transmission electron microscopy can image individual TiO(2) nanocrystals with a resolution of 70 pm while exposing the specimen to a low dose of electrons. Our approach, which does not require spherical and chromatic aberration correction, can reveal the location of light atoms (oxygen) in the crystal lattice. We find that the unit cell in nanoscale TiO(2) is subtly different to that in the corresponding bulk.

Hybrid halide perovskite solar cells generally show differences in the power output depending on the voltage sweep direction, an undesired phenomenon termed hysteresis. Although the causes of this behavior have not yet been univocally determined, commonly, hysteresis heavily affects solar cells based on flat TiO2 as electron extracting layer. Herein, it is shown how perovskite material quality has a preeminent impact on hysteresis, and how combined deposition and post-deposition engineered manufacturing could lead to highly efficient and hysteresis-less solar cells, notwithstanding a planar TiO2-based layout. This methodology relies on solvent engineering during the casting process, leading to an ultra-flat, uniform, and thick film ensuring an optimal interface connection with the charge-extracting layer combined with post-deposition thermal and vacuum treatments, which merge the crystalline domains and cure the defects at the grain boundaries. This method allows obtaining perovskite active layer with superior optical properties, explaining the ideal device behavior and performances, therefore, a simple optimization of perovskite processing conditions can efficiently stem hysteresis targeting different device layouts. Power conversion efficiency of 15.4% and reduced hysteresis are achieved.

In this work, the use of unconventional reference materials to determine experimentally the Cliff-Lorimer factor for EDS quantitative analysis with a TEM is checked by means of an alternative experimental procedure. The k-factor is determined by the extrapolation method based on pure elements, by measuring the normalized X-ray intensities emitted by thin films of pure gold and pure silver of different thickness, accurately measured by X-ray reflectivity. The goal of this work is to confirm the value of the k-factor previously obtained by the use of unconventional reference materials consisting of a bi-layer of pure gold on pure silver. The current result is in accordance with the previous one when considering their error bars, however, their relative difference is about 13 %, probably due to some uncertainties in mass thickness measurements. The mass thickness measurement of the layers of pure elements needs to be performed by different methods in order to reduce its uncertainty.

A new method for achieving high efficiency planar CH3NH3I3-xClx perovskite photovoltaics, based on a low pressure, reduced temperature vapor annealing is demonstrated. Heterojunction devices based on this hybrid halide perovskite exhibit a top PCE of 16.8%, reduced J-V hysteresis, and highly repeatable performance without need for a mesoporous or nanocrystalline metal oxide layer. Our findings demonstrate that large hysteresis is not an inherent feature of planar heterojunctions, and that efficient charge extraction can be achieved with uniform halide perovskite materials with desired composition. X-ray diffraction, valence band spectroscopy, and transient absorption measurements of these thin films reveal that structural modifications induced by chlorine clearly dominate over chemical and electronic doping effects, without affecting the Fermi level or photocarrier lifetime in the material.

Here, we propose the use of magnetic hyperthermia as a means to trigger the oxidation of Fe1-xO/Fe3-delta O4 core-shell nanocubes to Fe3-delta O4 phase. As a first relevant consequence, the specific absorption rate (SAR) of the initial core-shell nanocubes doubles after exposure to 25 cycles of alternating magnetic field stimulation. The improved SAR value was attributed to a gradual transformation of the Fe-1 O-x core to Fe3-delta O4, as evidenced by structural analysis including high resolution electron microscopy and Rietveld an alysis of X-ray diffraction patterns. The magnetically oxidized nanocubes, having large and coherent Fe3-delta O4 domains, reveal high saturation magnetization and behave superparamagnetically at room temperature. In comparison, the treatment of the same starting core-shell nanocubes by commonly used thermal annealing process renders a transformation to gamma-Fe2O3. In contrast to other thermal annealing processes, the method here presented has the advantage of promoting the oxidation at a macroscopic temperature below 37 degrees C. Using this soft oxidation process, we demonstrate that biotin-functionalized core-shell nanocubes can undergo a mild self-oxidation transformation without losing their functional molecular binding activity.

The increasing demand of piezoelectric energyharvesters for wearable and implantable applications requiresbiocompatible materials and careful structural device design, payingspecial attention to the conformability characteristics, properlytailored to scavenge continuously electrical energy even from thetiniest body movements. This paper provides a comprehensive studyon a flexible and biocompatible aluminum nitride (AlN) energyharvester based on a new alternative fabrication approach, exploiting athin polyimide (PI) substrate, prepared by spin coating of precursorssolution. This strategy allows manufacturing substrates with adjustablethickness to meet conformability requirements. The device isbased on a piezoelectric AlN thin film, sputtered directly onto the softPI substrate, without poling/annealing processes and patterned bysimple and low cost microfabrication technologies. AlN active layer,grown on soft substrate, exhibits good morphological and structural properties with roughness root mean squared (Rrms) of 6.35nm, columnar texture and (002) c-axis orientation. Additionally, piezoelectric characterization has been performed and theextracted piezoelectric coefficient value of AlN thin film resulted to be 4.93 ± 0.09 pm/V. The fabricated flexible AlN energyharvester generates an output peak-to-peak voltage of ~1.4 V and a peak-to-peak current up to 1.6 ?A, under periodicaldeformation, corresponding to a current density of 2.1 ?A/cm2, and providing a maximum generated power of 1.57 ?W underoptimal resistive load. Furthermore, the AlN energy harvester exhibits high elasticity and resistance to mechanical fatigue. Highquality AlN piezoelectric layers on elastic substrates with tunable thicknesses pave the way for the development of astraightforward technological platform for wearable/implantable energy harvesters and biomechanical sensors.

Short peptides or single amino acids are interesting building blocks for hydrogels fabrication, frequently used as extracellular matrix-mimicking scaffolds for cell growth in tissue engineering. The combination of two or more peptide hydrogelators could allow the obtaining of different materials exhibiting new architectures, tunable mechanical properties, high stability and improved biofunctionality. Here we report on the synthesis, formulation and multi-scale characterization of peptidebased mixed hydrogels formed by the low molecular weight Fmoc-FF (N?-fluorenylmethyloxycarbonyl diphenylalanine) hydrogelator and of the PEG8-(FY)3 hexapeptide, containing three repetitions of Phe-Tyr motif and a PEG moiety at its Nterminus. Mixed hydrogels were also prepared replacing PEG8-(FY)3 with its analogue (FY)3, without the PEG moiety. Rheology analysis confirmed the improved mechanical features of the multicomponent gels prepared at two different ratios (2/1 or 1/1, v/v). However, the presence of the hydrophilic PEG polymeric moiety causes a slowing down of the gel kineticformation (from 42 to 18 minutes) and a decrease of the gel rigidity (G' from 9 to 6 kPa). Preliminary in vitro biocompatibility and cell adhesion assays performed on Chinese Hamster Ovarian (CHO) suggest a potential employ of these multicomponent hydrogels as exogenous scaffold materials for tissue engineering.

The engineering of electrochemically active films based on structurally and geometrically controlled transitionmetaloxide nanocrystals holds promise for the development of a new generation of energy-efficient dynamicwindows that may enable a spectrally selective control of sunlight transmission over the near-infrared regime.Herein, the different spectro-electrochemical signatures of two sets of engineered nanotextured electrodes madeof distinct anisotropic-shaped tungsten oxide building blocks are comparatively investigated. The electrodeswere fabricated starting from corresponding one-dimensional colloidal nanocrystals, namely solid and longitudinallycarved nanorods, respectively, which featured identical crystal phase and lattice orientation, butexposed two distinct space-filled volume structures with subtly different lattice parameters and nonequivalenttypes of accessible surfaces. The shape of nanocrystalline building blocks greatly impacted on the fundamentalelectrochemical charge-storage mechanisms and, hence on the electrochromic response of these electrodes, dueto concomitant bulk and surface-structure effects that could not be entirely traced to mere differences in surfaceto-volume ratio. Electrodes made of carved nanorods accommodated more than 80% of the total charge throughsurface-capacitance mechanisms. This unique prerogative was ultimately demonstrated to enable an outstandingspectral selectivity as well as an extremely efficient dynamic modulation of the optical transmittance at nearinfraredfrequencies (~ 80% in the range 700-1600 nm).

Organic capped Au nanoparticles (NPs) and PbS quantum dots (QDs), synthesized with high control on size and size distribution, were used as building blocks for fabricating solid crystals by solvent evaporation. The superlattice formation process for the two types of nano-objects was investigated as a function of concentration by means of electron microscopy and X-ray techniques. The effect of building block composition, size, geometry, and concentration and the role of the organic coordinating molecules was related to the degree of order in the superlattices. A convenient combination of different complementary X-ray techniques, namely in situ and ex situ GISAXS and GIWAXS, allowed elucidating the most reliable signatures of the superlattices at various stages of the self-assembly process, since their early stage of formation and up to few months of aging. Significantly different assembly behaviour was assessed for the two types of NPs, clearly explained on the basis of their chemical composition, ultimately reflecting on the assembling process and on the final structure characteristics.

Semiconductor/metal nanocomposites based on anatase TiO2 nanoparticles and Au nanorods (TiO2/AuNRs) were prepared by means of a co-precipitation method and subsequently calcinated at increasing temperature (from 250° to 650°C) obtaining up to 20 grams of catalysts. The structure and the morphology of the obtained nanocomposite material were comprehensively characterized by means of electron microscopy (SEM and TEM) and X-ray diffraction techniques. The photocatalytic performance of the TiO2/AuNRs nanocomposites was investigated as a function of the calcination temperature in experiment of degradation of water pollutants under both UV and UV-Vis irradiation, Photocatalytic experiments under UV irradiation were performed by monitoring spectrophotometrically the decolouration of a target compound (methylene blue, MB) in aqueous solution. UV-Visible light irradiation was, instead, used for testing the photocatalytic removal of an antibiotic molecule, Nalidixic acid, by monitoring the degradation process by HPLC-MS analysis. Interestingly, TiO2/AuNRs calcined at 450°C was up to 2.5 and 3.2 times faster than TiO2P25 Evonik, that is a commercially available reference material, in the photocatalytic degradation of the Methylene Blue and the Nalidixic Acid, under UV and visible light, respectively. The same nanocomposite material showed a photocatalytic degradation rate for the two target compounds up to 13 times faster than the bare TiO2-based catalysts.The obtained results are explained on the basis of the structure and morphology of the nanocomposites, that could be tuned according to the preparative conditions. The role played by the plasmonic domain in the heterostructured materials, either under UV and UV-Visible illumination, is also highlighted and discussed.The overall results indicate that the high photoactivity of TiO2/AuNRs in the visible range can be profitably exploited in photocatalytic applications, thanks also to the scalability of the proposed synthetic route, thus ultimately envisaging potential innovative solution for environmental remediation.

Despite the growing literature about diphenylalanine-based peptide materials, it still remains a challenge to delineate the theoretical insight into peptide nanostructureformation and the structural features that could permit materials with enhanced properties to be engineered. Herein, we report the synthesis of a novel peptide building blockcomposed of six phenylalanine residues and eight PEG units, PEG8-F6. This aromatic peptide self-assembles in water in stable and well-ordered nanostructures with optoelectronic properties. A variety of techniques, such as fluorescence, FTIR, CD, DLS, SEM, SAXS, and WAXS allowed us to correlate the photoluminescence properties of the self-assembled nanostructures with the structural organization of the peptide building block at the micro- and nanoscale. Finally, a model of hexaphenylalanine in aqueous solution by molecular dynamics simulations is presented to suggest structural and energetic factors controlling the formation of nanostructures.

The replacement of diseased tissues with biological substitutes with suitablebiomechanical properties is one of the most important goal in tissue engineering. Collagenrepresents a satisfactory choice for scaffolds. Unfortunately, the lack of elasticity represents arestriction to a wide use of collagen for several applications. In this work, we studied theeffect of human elastin-like polypeptide (HELP) as hybrid collagen-elastin matrices. Inparticular, we studied the biomechanical properties of collagen/HELP scaffolds ...

A colloidal crystal-splitting growth regime has been accessed, in which TiO2 nanocrystals, selectively trapped in the metastable anatase phase, can evolve to anisotropic shapes with tunable hyperbranched topologies over a broad size interval. The synthetic strategy relies on a nonaqueous sol-gel route involving programmed activation of aminolysis and pyrolysis of titanium carboxylate complexes in hot surfactant media via a simple multi-injection reactant delivery technique. Detailed investigations indicate that the branched objects initially formed upon the aminolysis reaction possess a strained monocrystalline skeleton, while their corresponding larger derivatives grown in the subsequent pyrolysis stage accommodate additional arms crystallographically decoupled from the lattice underneath. The complex evolution of the nanoarchitectures is rationalized within the frame of complementary mechanistic arguments. Thermodynamic pathways, determined by the shape-directing effect of the anatase structure and free-energy changes accompanying branching and anisotropic development, are considered to interplay with kinetic processes, related to diffusion-limited, spatially inhomogeneous monomer fluxes, lattice symmetry breaking at transient Ti5O5 domains, and surfactant-induced stabilization. Finally, as a proof of functionality, the fabrication of dye-sensitized solar cells based on thin-film photoelectrodes that incorporate networked branched nanocrystals with intact crystal structure and geometric features is demonstrated. An energy conversion efficiency of 6.2% has been achieved with standard device configuration, which significantly overcomes the best performance ever approached with previously documented prototypes of split TiO2 nanostructures. Analysis of the relevant photovoltaic parameters reveals that the utilized branched building blocks indeed offer light-harvesting and charge-collecting properties that can overwhelm detrimental electron losses due to recombination and trapping events.

We exploit TiO2 surface functionalization as a tool to induce the crystallization process of CH3NH3PbI3
xClxperovskite thin films resulting in a reduction of the degree of orientation of the (110) crystallographic planes.Notably, the variation of the film crystalline orientational order does not affect the photovoltaicperformances of the perovskite-based devices, whose efficiency remains mostly unchanged. Ourfindings suggest that other factors are more significant in determining the device efficiency, such as thenon-homogenous coverage of the TiO2 surface causing charge recombination at the organic/TiO2interface, defect distribution on the perovskite bulk and at the interfaces, and transport in the organic orTiO2 layer. This observation represents a step towards the comprehension of the perovskite filmpeculiarities influencing the photovoltaic efficiency for high performance devices.

SnO2 nanocrystals were prepared by precipitation in dodecylamine at 100°C, then they were reacted with vanadium chloromethoxide in oleic acid at 250°C. The resulting materials were heat-treated at various temperatures up to 650°C for thermal stabilization, chemical purification and for studying the overall structural transformations. From the crossed use of various characterization techniques, it emerged that the as-prepared materials were constituted by cassiterite SnO2 nanocrystals with a surface modified by isolated V(IV) oxide species. After heat-treatment at 400°C, the SnO2 nanocrystals were wrapped by layers composed of vanadium oxide (IV-V mixed oxidation state) and carbon residuals. After heating at 500°C, only SnO2 cassiterite nanocrystals were obtained, with a mean size of 2.8nm and wrapped by only V2O5-like species. The samples heat-treated at 500°C were tested as RhB photodegradation catalysts. At 10-7M concentration, all RhB was degraded within 1h of reaction, at a much faster rate than all pure SnO2 materials reported until now.

Nucleophosmin (NPM1) is a multifunctional protein involved in a variety of biological processes including the pathogenesis of several human malignancies and is the most frequently mutated gene in Acute Myeloid Leukemia (AML). To deepen the role of protein regions in its biological activities, lately we reported on the structural behavior of dissected C-terminal domain (CTD) helical fragments. Unexpectedly the H2 (residues 264-277) and H3 AML-mutated regions showed a remarkable tendency to form amyloid-like assemblies with fibrillar morphology and beta-sheet structure that resulted toxic when exposed to human neuroblastoma cells. More recently NPM1 was found to be highly expressed and toxic in neurons of mouse models of Huntington's disease (HD). Here we investigate the role of each residue in the beta-strand aggregation process of H2 region of NPM1 by performing a systematic alanine scan of its sequence and structural and kinetic analyses of aggregation of derived peptides by means of Circular Dichorism (CD) and Thioflavin T (Th-T) assay. These solution state investigations pointed out the crucial role exerted by the basic amyloidogenic stretch of H2 (264-271) and to shed light on the initial and main interactions involved in fibril formation we performed studies on fibrils deriving from the related Ala peptides through the analysis of fibrils with birefringence of polarized optical microscopy and wide-angle X-ray scattering (WAXS). This analysis suggested that the presence of branched Ile(269) conferred preferential packing patterns that, instead, appeared geometrically hampered by the aromatic side-chain of Phe(268). Present investigations could be useful to deepen the knowledge of AML molecular mechanisms and the role of cytoplasmatic aggregates of NPM1c+.

Biosystems integration into an organic field-effect transistor (OFET)structure is achieved by spin coating phospholipid or protein layersbetween the gate dielectric and the organic semiconductor. Anarchitecture directly interfacing supported biological layers to theOFET channel is proposed and, strikingly, both the electronic propertiesand the biointerlayer functionality are fully retained. Theplatform bench tests involved OFETs integrating phospholipids andbacteriorhodopsin exposed to 1-5% anesthetic doses that revealdrug-induced changes in the lipid membrane. This result challengesthe current anesthetic action model relying on the so far providedevidence that doses much higher than clinically relevant ones(2.4%) do not alter lipid bilayers' structure significantly. Furthermore,a streptavidin embedding OFET shows label-free biotin electronicdetection at 10 parts-per-trillion concentration level, reachingstate-of-the-art fluorescent assay performances. These examplesshow how the proposed bioelectronic platform, besides resultingin extremely performing biosensors, can open insights into biologicallyrelevant phenomena involving membrane weak interfacialmodifications.

Bovine cornea was studied with scanning small-angle X-ray scattering (SAXS) microscopy, by using both synchrotron radiation and a microfocus laboratory source. A combination of statistical (adaptive binning and canonical correlation analysis) and crystallographic (pair distribution function analysis) approaches allowed inspection of the collagen lateral packing of the supramolecular structure. Results reveal (i) a decrease of the interfibrillar distance and of the shell thickness around the fibrils from the periphery to the center of the cornea, (ii) a uniform fibril diameter across the explored area, and (iii) a distorted quasi-hexagonal arrangement of the collagen fibrils. The results are in agreement with existing literature. The overlap between laboratory and synchrotron-radiation data opens new perspectives for further studies on collagen-based/engineered tissues by the SAXS microscopy technique at laboratory-scale facilities.Bovine cornea was studied with scanning small-angle X-ray scattering microscopy, by using both synchrotron radiation and a microfocus laboratory source. The supramolecular structure of the collagen fibers is explored thanks to the combination of statistical (adaptive binning and canonical correlation analysis) and crystallographic (pair distribution function analysis) approaches.

This paper describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity "particles factory", based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics,chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE is also supposed to be realized in subsequent stages of development depending on the assigned priorities.

Electron diffractive imaging (EDI) relies on combining information from the high-resolution transmission electron microscopy image of an isolated kinematically diffracting nano-particle with the corresponding nano-electron diffraction pattern. Phase-retrieval algorithms allow one to derive the phase, lost in the acquisition of the diffraction pattern, to visualize the actual atomic projected potential within the specimen at sub-ångström resolution, overcoming limitations due to the electron lens aberrations. Here the approach is generalized to study extended crystalline specimens. The new technique has been called keyhole electron diffractive imaging (KEDI) because it aims to investigate nano-regions of extended specimens at sub-ångström resolution by properly confining the illuminated area. Some basic issues of retrieving phase information from the EDI/KEDI measured diffracted amplitudes are discussed. By using the generalized Shannon sampling theorem it is shown that whenever suitable oversampling conditions are satisfied, EDI/KEDI diffraction patterns can contain enough information to lead to reliable phase retrieval of the unknown specimen electrostatic potential. Hence, the KEDI method has been demonstrated by simulations and experiments performed on an Si crystal cross section in the [112] zone-axis orientation, achieving a resolution of 71 pm.

For both fundamental study of biological processes and early diagnosis of diseases, information about nanoscale changes in tissue and cell structure is crucial. Nowadays, almost all currently known nanoscopy methods rely upon the contrast created by fluorescent stains attached to the object or molecule of interest. This causes limitations due to the impact of the label on the object and its environment, as well as its applicability in vivo, particularly in humans. In this paper, a new label-free approach to visualize small structure with nano-sensitivity to structural alterations is introduced. Numerically synthesized profiles of the axial spatial frequencies are used to probe the structure within areas whose size can be beyond the diffraction resolution limit. Thereafter, nanoscale structural alterations within such areas can be visualized and objects, including biological ones, can be investigated with sub-wavelength resolution, in vivo, in their natural environment. Some preliminary results, including numerical simulations and experiments, which demonstrate the nano-sensitivity and super-resolution ability of our approach, are presented.

We use ultrafast transient absorption microscopy to map the effect of structural disorder on the photophysical properties within a micrometer-sized crystal of methylammonium lead iodide (CH3NH3PbI3) perovskite. We reveal a spatial inhomogeneity of the structural and photophysical behavior on the submicrometer scale induced by a local distortion of the crystal lattice, which affects the electron hole correlation over the hundreds of nanometers length scale.

Hybrid halide perovskites are soft materials processed at room temperature, revolutionary players in the photovoltaic field. Nowadays, investigation of the nature and roleof defects is seen as one of the key challenges toward full comprehension of their behavior and achievement of high device stability under working conditions. We reveal the reversible generation, under illumination, of paramagnetic Pb3+ defects in CH3NH3PbI3, synthesized in ambient conditions, induced by the presence of Pb-O defects in the perovskite structure that may trap photogenerated holes, possibly mediated by the concomitant oxidation and migration of ions. According to the mechanism thatwe hypothesize, one charge is trapped for each paramagnetic center generated; thus, it does not contribute to the photocurrent,potentially limiting the solar cell performance. Our study, based on combined experimental/theoretical approach, reveals the dynamic evolution of the perovskite characteristics under illumination that needs to be considered when investigating the material physical-chemical properties.

In recent years synchrotron x-ray microprobes and nanoprobes have emerged as key characterization tools with a remarkable impact for different scientific fields including solid-state, applied, high-pressure, and nuclear physics, chemistry, catalysis, biology, and cultural heritage. This review provides a comparison of the different probes available for the space-resolved characterization of materials (i. e., photons, electrons, ions, neutrons) with particular emphasis on x rays. Subsequently, an overview of the optics employed to focus x rays and the most relevant characterization techniques using x rays (i. e., x-ray diffraction, wide-angle x-ray scattering, small-angle x-ray scattering, x-ray absorption spectroscopy, x-ray fluorescence, x-ray-excited optical luminescence, and photoelectron spectroscopy) is reported. Strategies suitable to minimize possible radiation damage induced by brilliant focused x-ray beams are briefly discussed. The general concepts are then exemplified by a selection of significant applications of x-ray microbeams and nanobeams to materials science. Finally, the future perspectives for the development of nanoprobe science at synchrotron sources and free-electron lasers are discussed.

Nanocrystal superlattices are attracting significant interest due to novel and peculiar collective properties arising from the interactions of the nanocrystals forming the superlattice. A large variety of superlattice structures can be obtained, involving one or more types of nanocrystals, with different sizes and concentrations. Engineering of the superlattice properties relies on accurate structural and morphological characterization, able to provide not only a fundamental feedback for synthesis procedures, but also relevant insight into their structural properties for possible applications. Electron microscopy and X-ray based techniques are complementary approaches for nanoscale structural imaging, which however become challenging in the presence of building blocks only a few nanometers in size. Here, a structure solution for a three-dimensional (3D) self-assembly of PbS nanocrystals with bimodal size distribution is obtained, by exploiting small-angle X-ray diffraction, transmission electron microscopy, crystallographic procedures, and geometric constraints. In particular, analysis of small-angle X-ray diffraction data, based on the Patterson function and on the single crystal model, is shown to provide relevant information on the 3D superlattice structure as well as on particle size, the scattering signal being sensitive to particles as small as 1.5 nm. The combined approach here proposed is thus demonstrated to effectively overcome important resolution limitations in the imaging of superlattices including small nanocrystals.

In the realm of semiconductor nanomaterials, a crystal lattice heavily doped with cation/anion vacancies or ionized atomic impurities is considered to be a general prerequisite to accommodating excess free carriers that can support localized surface plasmon resonance (LSPR). Here, we demonstrate a surfactant-assisted nonaqueous route to anisotropic copper sulfide nanocrystals, selectively trapped in the covellite phase, which can exhibit intense, size-tunable LSPR at near-infrared wavelengths despite their stoichiometric, undoped structure. Experimental extinction spectra are satisfactorily reproduced by theoretical calculations performed by the discrete dipole approximation method within the framework of the Drude-Sommerfeld model. The LSPR response of the nanocrystals and its geometry dependence are interpreted as arising from the inherent metallic-like character of covellite, allowed by a significant density of lattice-constitutional valence-band free holes. As a consequence of the unique electronic properties of the nanocrystals and of their monodispersity, coherent excitation of symmetric radial breathing modes is observed for the first time in transient absorption experiments at LSPR wavelengths.

An efficient microwave-assisted synthesis of TiO2:(B) nanorods, using titanium tetraisopropoxide (TTIP), benzyl alcohol as the solvent, together with boric acid and oleic acid as the additive reagents, has been developed. Chemical modification of TTIP by oleic acid was demonstrated as a rational strategy to tune the shape of TiO2 nanocrystals toward nanorod formation. The differently-shaped TiO2:(B) nanocrystals were characterized in detail by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and nitrogen absorption-desorption. Oleic acid coordinated on the nanocrystal surface was removed by the reduction of its carboxyl group, and the photocatalytic activity of bare TiO2 nanocrystals, under visible light irradiation, was also evaluated. The synthesized TiO2 anatase nanorods exhibited a good photoactivity and completely degraded Rhodamine B solution within three hours.

Novel photosensitizing film based on the natural hybrid polymer Chitosan/2-hydroxy-propyl-b-Cyclodextrin(CH/CD) is synthesized introducing Chlorophyll a (CH/CD/Chla) as a photoactive agent forpossible application in antimicrobial photodynamic therapy (PDT). The polymer absorbs visible light, inturn able to generate reactive oxygen species (ROS) and, therefore it can be used as environmentalfriendly and biodegradable polymeric photosensitizer (PS). The modified film is characterized by meansof different spectroscopic, calorimetric, diffraction techniques and microscopic imaging methodsincluding time-resolved absorption spectroscopy. UVeVis, FTIR-ATR and X-ray Photoelectron Spectroscopy(XPS) analyses suggest that Chla shows a strong affinity toward Chitosan introducing interactionswith amino groups present on the polymer chains. Nanosecond laser flash photolysis technique providesevidence for the population of the excited triplet state of Chla. Photogeneration of singlet oxygen isdemonstrated by both direct detection by using infrared luminescence spectroscopy and chemicalmethods based on the use of suitable traps. Scanning Electron Microscopy (SEM), Atomic Force Microscopy(AFM) and Differential Scanning Calorimetry (DSC) analyses confirm also the occurrence ofstructural changes both on the film surface and within the film layer induced by the insertion of thepigment. Moreover, X-ray Diffraction data (XRD) shows the existence of an amorphous phase for thechitosan films in all the compared conditions.

The photocatalytic degradation of pollutants is a key technological application for nanomaterials. Ourwork aims at developing a multifunctional nanocrystalline heterostructure based on TiO2nanorods,FexOyand Ag nanoparticles (NPs), TiO2NRs/FexOy/Ag, integrating in one nanostructure a visible lightphotoactive moiety (TiO2NRs/Ag) and a magnetic domain (FexOy), in order to address the photoactivityunder visible light and the possibility of recovery and reuse the photocatalyst. The synthesis was carriedby preparing first the TiO2NRs/FexOybased heterostructure and then growing Ag NPs with control on size.The resulting multidomain structures were characterized by FTIR and absorption spectroscopy, TEM andSEM microscopy, EDS and XRD analysis. The influence of the Ag NP domain and of its size on the photoac-tivity of the TiO2NRs/FexOy/Ag nanostructures under visible light were investigated in the photocatalyticdegradation of the Nalidixic Acid, an antibiotic used as a model compound representative of recalci-trant pollutants. In the presence of the Ag domain a significant increase of the photoactivity with respectto TiO2NRs/FexOyheterostructures and to the commercially available TiO2P25 was observed. Such anenhanced photocatalytic efficiency was found dependent on the size of the Ag domain and explainedtaking into account the plasmonic properties and the different possible photoactivation mechanisms.

Transition-metal alkane-thiolates (i.e., organic salts with formula Me(SR)x,where R is a linear aliphatic hydrocarbon group, -CnH2n+1) undergo a thermolysis reactionat moderately low temperatures (close to 200 °C), which produces metal atoms or metalsulfide species and an organic by-product, disulfide (RSSR) or thioether (RSR) molecules,respectively. Alkane-thiolates are non-polar chemical compounds that dissolve inmost techno-polymers and the resulting solid solutions can be annealed to generatepolymer-embedded metal or metal sulfide clusters. Here, the preparation of silver and goldclusters embedded into amorphous polystyrene by thermolysis of a dodecyl-thiolateprecursor is described in detail. However, this chemical approach is quite universal and alarge variety of polymer-embedded metals or metal sulfides could be similarly prepared.

PbS colloidal nanocrystal (NC) assemblies with monomodal and bimodal size distribution have been fabricated by slow evaporation of solvent on silicon substrates. The interparticle distances of the assembled structures have been carefully defined, both in the plane and in the z direction, perpendicular to the substrate, thanks to the combination of small and wide-angle X-ray diffraction and TEM measurements. The spectroscopic characteristics of PbS NCs, both in solution and organized in a superlattice, have been investigated by steady-state and time-resolved photoluminescence measurements. The optical results reveal the occurrence of a Forster resonant energy transfer (FRET) mechanism between closed-packed neighboring PbS NCs. The occurrence of FRET is dependent on NC assembly geometry, and thus on their interparticle distance, suggesting that only when NCs are close enough, as in the close-packed arrangement of the monomodal assembly, the energy transfer can be promoted. In bimodal assemblies, the energy transfer between large and small NCs is negligible, due to the low spectral overlap between the emission and absorption bands of the different sized nanoparticles and to the large interparticle distance. Moreover, recombination lifetimes on the microsecond time scale have been observed and explained in terms of dielectric screening effect, in agreement with previous findings on lead chalcogenide NC optical properties.

Recent developments in the exploitation of transparent conductive oxide nanocrystals paved the way to the realization of a new class of electrochemical systems capable of selectively shielding the infrared heat loads carried by sunlight and prospected the blooming of a key enabling technology to be implemented in the next generation of "zero-energy" building envelopes. Here we report the fabrication of a set of electrochromic devices embodying an engineered nanostructured electrode made by high aspect-ratio tungsten oxide nanorods, which allow for selectively and dynamically controlling sunlight transmission over the near-infrared to visible range. Varying the intensity of applied voltage makes the spectral response of the device change across three different optical regimes, namely fully transparent, near-infrared only blocking and both visible and near-infrared blocking. It is demonstrated that the degree of reversible modulation of the thermal radiation entering the glazing element can approach a remarkable 85%, accompanied by only a modest reduction in the luminous transmittance.

A simple synthesis was applied and tested for the preparation of boron-doped titanium dioxide [TiO2(B)] nanocrystals using titanium tetraisopropoxide (TTIP) together with boric acid (H3BO3) and benzyl alcohol as reaction solvent. Changes in the TTIP/H3BO3 molar ratio allowed a scalable synthetic protocol with a significant B-dopant control. In particular, this approach does not need surfactants or a final calcination step. X-ray diffractometry (XRD), low- and high-resolution transmission electron microscopy (TEM and HRTEM), and micro Raman spectroscopy revealed that the TiO2 nanocrystals produced have diameters up to about 10 nm and are mainly of the anatase phase but that a brookite phase was progressively formed with increased dopant level. The amount of boron was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the presence of boron inside the crystals was determined by 11B cross-polarized magic-angle spinning nuclear magnetic resonance (11B CP-MAS NMR) spectroscopy. X-ray photoelectron spectroscopy (XPS) revealed the presence of boron on the nanocrystal surfaces, confirming the trend in the dopant concentration already observed with ICP-AES elemental analysis. Microphotoluminescence studies indicated the formation of three different typical luminescent defect states in correlation with the amount of added boron in the titania. UV/Vis absorption spectra showed a boron-dependent redshift of the absorption edge.

Progress in the emerging areas of science and technology, such as bio- and nano-technologies, depends on development of corresponding techniques for imaging and probing the structures with high resolution. Recently, the far field diffraction resolution limit in the optical range has been circumvented and different methods of super-resolution optical microscopy have been developed. The importance of this breakthrough achievement has been recognized by Nobel Prize for Chemistry in 2014. However, the fluorescence based super-resolution techniques only function with fluorescent molecules (most of which are toxic and can destroy or lead to artificial results in living biological objects) and suffer from photobleaching. Here we show a new way to break the diffraction resolution limit, which is based on nano-sensitivity to internal structure. Instead of conventional image formation as 2D intensity distribution, in our approach images are formed as a result of comparison of the axial spatial frequency profiles, reconstructed for each image point. The proposed approach dramatically increases the lateral resolution even in presence of noise and allows objects to be imaged in their natural state, without any labels.

We report a phosphine-free synthesis of p-type copper(I) selenide nanocrystals by a colloidal approach in a mixture of oleylamine and 1-octadecene. The nanocrystals had a cuboctahedral shape and cubic berzelianite phase. Films of these nonstoichiometric copper-deficient Cu2-xSe nanocrystals were highly conductive and showed high absorption coefficient in the near-infrared region. These nanocrystals could be used as hole-injection layers in optoelectronic devices.

In this work, the self-cleaning and photocatalytic properties of mesoporousTiO2/AuNRs-SiO2 composites (namely UCA-TiO2Au) prepared by a simple and low-costtechnique were investigated toward application in building materials. Mesoporous photocatalyticnanocomposites coating the surface of stone and other building materials are a very promisingapproach to address relevant questions connected with the increasing atmospheric pollution.We tested three types of preformed TiO2/AuNRs nanostructures in order to evaluate the effectof AuNRs on the photocatalytic activity of resulting coatings deposited on the surface of apopular building limestone. The resulting nanocomposites provide crack-free surface coatingson limestone, effective adhesion, improve the stone mechanical properties and impart hydrophobicand self-cleaning properties. Photocatalytic characterization involved the degradation of a targetcompound (Methylene blue; MB) under direct exposure to simulated solar light using TiO2 P25 Evonik(TiO2 P25) as a reference material. Moreover, these coatings upon irradiation by simulated solarlight were successfully employed for the photocatalytic oxidation of carbon soot. The experimentalresults revealed that UCA-TiO2Au samples are the best performing coating in both MB bleachingand soot degradation.

A great interest has been recently generated by the discovery that peptide-based nanostructures (NSs) endowed with cross-beta structure may show interesting photoluminescent (PL) properties. It was shown that NSs formed by PEGylated hexaphenylalanine (PEG(8)-F6, PEG=polyethylene glycol) are able to emit at 460 nm when excited at 370 or 410 nm. Here, the possibility to transfer the fluorescence of these PEG(8)-F6-based NSs by foster resonance electron transfer (FRET) phenomenon to a fluorescent dye was explored. To achieve this aim, the 4-chloro-7-nitrobenzofurazan (NBD) dye was encapsulated in these NSs. Structural data in solution and in solid state, obtained by a variety of techniques (circular dichroism, Fourier-transform infrared spectroscopy, wide-angle X-ray scattering, and small-angle X-ray scattering), indicated that the organization of the peptide spine of PEG(8)-F6 NS, which consists of anti-parallel beta-sheets separated by a dry interface made of interacting phenylalanine side chains, was maintained upon NBD encapsulation. The spectroscopic characterization of these NSs clearly showed a redshift of the emission fluorescence peak both in solution and in solid state. This shift from 460 to 530 nm indicated that a FRET phenomenon from the peptide-based to the fluorophore-encapsulated NS occurred. FRET could also be detected in the PEG(8)-F6 conjugate, in which the NBD was covalently bound to the amine of the compound. On the basis of these results, it is suggested that the red-shift of the intrinsic PL of NSs may be exploited in the bio-imaging field.

In the last few years, new drug delivery systems have been as one of the fewest responses for the treatment of the most aggressive diseases, including cancer. In this perspective, inorganic nanocrystals (NCs) offer the potential for a new and innovative approach for the targeted transport of drugs towards tissues affected by disease. A very important aspect is represented by the determination of the maximum cellular dose of these nanovectors, that is relevant for diagnostic and therapeutic applications both in-vitro and in-vivo tests [1]. Furthermore, the concentration of the nanovector is mandatory for the thorough characterization of the product required for any regulatory approval [2]. Accurate determination of the concentration is not a trivial issue and currently there is a lack of experimental methods recognized as general and reliable [3]. In this work, we propose an approach for the determination of the concentration of a solid lipid nanoparticle (SLN) nanovector encapsulating photoactive copper sulfide (Cu2-xS) NCs characterized by a tunable localized surface plasmon resonance (LSPR) in the near-infrared (NIR) spectral region, that is highly transparent for tissue, blood, and water [4]. Here, Cu2-xS NCs, synthesized by hot injection method, carefully tuning reaction conditions in order to achieve NCs with a narrow size distribution and an intense LSPR in the second biological window, have been encapsulated into SLN prepared by a hot homogenization technique using a mixture of cholesterol and triglycerides and phospholipids. A calculation method based on Mie-Drude theory using as input data resulting from spectroscopic characterization and transmission electron microscopy (TEM) and dynamic light scattering (DLS) investigation for the Cu2-xS NCs and NCs containing SLNs successfully provide the determination of the nanovector concentration (Figure 1). The results are in agreement with experimental data and such an approach represent a powerful tool for determining the concentration of plasmonic NCs based nanovectors regardless of their degree of complexity.

An efficient microwave supported synthesis, with a reaction time of only one and a half minute, to prepare boron-modified titania nanocrystals TiO2:(B), was developed. The nanocrystals were obtained by hydrolysis of titanium tetraisopropoxide (TTIP) together with benzyl alcohol and boric acid, and the approach did not need surfactants use and a final calcination step. The produced TiO2:(B) nanocrystals were characterized in detail by low magnification Transmission Electron Microscopy (TEM), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), X-Ray Diffractometry (XRD), and a Micro Raman Spectroscopy. One of the obtained samples was then tested as an additive in various amounts in a typical aluminosilicate refractory composition. The effects of these additions in bricks were evaluated, according to UNI EN 196/2005, in terms of thermo-physical and mechanical properties: diffusivity, bulk density, apparent density, open and apparent porosity and cold crushing strength. Bricks' microstructure was analysed by Scanning Electron Microscopy (SEM) and energy dispersion spectroscopy (EDS). The bricks obtained with nanoadditives presented improved mechanical characteristics with respect to the typical aluminosilicates, presumably because of a better compaction during the raw materials' mixing stage.

Research on composite materials is facing, among others, the challenging task of incorporating nanocrystals, and their superstructures, in polymer matrices. Electron microscopy can typically image nanometre-scale structures embedded in thin polymer films, but not in films that are micron size thick. Here, X-ray Ptychography was used to visualize, with a resolution of a few tens of nanometers, how CdSe/CdS octapod-shaped nanocrystals self-assemble in polystyrene films of 24 ± 4 ?m, providing a unique means for non-destructive investigation of nanoparticles distribution and organization in thick polymer films.

The nanoscale structural order of air-dried rat-tail tendon is investigated using small-angle X-ray scattering (SAXS). SAXS fiber diffraction patterns were collected with a superbright laboratory microsource at XMI-LAB [Altamura, Lassandro, Vittoria, De Caro, Siliqi, Ladisa & Giannini (2012). J. Appl. Cryst. 45, 869-873] for increasing integration times (up to 10 h) and a novel algorithm was used to estimate and subtract background, and to deconvolve the beam-divergence effects. Once the algorithm is applied, the peak visibility improves considerably and reciprocal space information up to the 22nd diffraction order is retrieved (q = 0.21 angstrom(-1), d = 29 angstrom) for an 8-10 h integration time. The gain in the visibility is already significant for patterns collected for 0.5 h, at least on the more intense peaks. This demonstrates the viability of detecting structural changes on a molecular/nanoscale level in tissues with state-of-the-art laboratory sources and also the technical feasibility to adopt SAXS fiber diffraction as a future potential clinical indicator for disease.

Films obtained by casting, starting from conventional emulsions (CE), nanoemulsions (NE) or their gels, whichled to different structures, with the aim of explore the relationship between structure and physical properties,were prepared. Sodium caseinate was used as the matrix, glycerol as plasticizer, glucono-delta-lactone asacidulant to form the gels, and TiO2 nanoparticles as reinforcement to improve physical behavior. Structuralcharacterization was performed by SAXS and WAXS (Small and Wide Angle X-ray Scattering, respectively),combined with confocal and scanning electron microscopy. The results demonstrate that the incorporation of thelipid phase does not notably modify the mechanical properties of the films compared to solution films. Filmsfrom NE were more stable against oil release than those from CE. Incorporation of TiO2 improved mechanicalproperties as measured by dynamical mechanical analysis (DMA) and uniaxial tensile tests. TiO2 macroscopicspatial distribution homogeneity and the nanostructure character of NE films were confirmed by mapping the qdependentscattering intensity in scanning SAXS experiments. SAXS microscopies indicated a higher intrinsichomogeneity of NE films compared to CE films, independently of the TiO2 load. NE-films containing structureswith smaller and more homogeneously distributed building blocks showed greater potential for food applicationsthan the films prepared from sodium caseinate solutions, which are the best known films.

Thanks to their high stability, good optoelectronic and extraordinary electrochromic properties, tungsten oxides are among the most valuable yet underexploited materials for energy conversion applications. Herein, colloidal one-dimensional carved nanocrystals of reduced tungsten trioxide (WO3-x) are successfully integrated, for the first time, as a hole-transporting layer (HTL) into CH3NH3PbI3 perovskite solar cells with a planar inverted device architecture. Importantly, the use of such preformed nanocrystals guarantees the facile solution-cast-only deposition of a homogeneous WO3-x thin film at room temperature, allowing achievement of the highest power conversion efficiency ever reported for perovskite solar cells incorporating raw and un-doped tungsten oxide based HTL.

Nowadays, there is strong interest in the development of smart inorganic nanostructured materials as tools for targeted delivery in cancer cells. We proposed a novel synthetic procedure of calcium carbonate nanocrystals (NCs) and their use as drug delivery systems, studying the physical chemical properties and the in vitro interaction with two model cancer cells.Pure and thermodynamically stable CaCO3 NCs in calcite phase were synthesized by a readily and feasible method, easily scalable, that allows the control of NCs shape and size without any surfactant use. CaCO3 NCs were extensively investigated by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Raman spectroscopy and Brunauer-Emmett-Teller analysis (BET). To deeper investigate their possible use as nanovectors for drug cancer therapies, CaCO3 NCs biocompatibility (by MTT assay), cell interaction and internalization were studied in in vitro experiments on HeLa and MCF7 cell lines. Confocal and transmission electron microscopies were used to monitor and evaluate NCs-cell interaction and cellular uptake.Data here reported demonstrated that synthesized NCs readily penetrate HeLa and MCF7 cells. NCs preferentially localize inside the cytoplasm, but were also found into mitochondria, nucleus and lysosomes. This study suggests that synthesized CaCO3 NCs are good candidates as effective intracellular therapeutic delivery system.

Osteoarthritis (OA), among other bone pathologies, is expected to determine supramolecular changes at the level of the mineralized collagen fiber. In a proof-of-principle study, bone biopsies were collected from six coxarthritis-affected patients, aged 62-87 years, during hip prosthesis implant surgery, sliced down to 100 mm-thick tissues, and investigated using scanning small-angle and wide-angle X-ray scattering (SAXS and WAXS) transmission microscopy. A multimodal imaging evaluation of the SAXS and WAXS data, combined with principal component and canonical correlation analyses, allowed the transformation of the raw data into microscopy images and inspection of the nanoscale structure of the mineralized collagen fibers across mm 2 tissue areas. The combined scanning SAXS and WAXS microscopy is shown to be a suitable choice for characterizing and quantifying the nanostructural properties of collagen over extended areas. The results suggest the existence of a correlation between age and cross-linking-induced rigidity of collagen fibers.

This study is aimed at investigating the structure of a scaffold made of bovine gelatin and hydroxyapatite for bone tissue engineering purposes. In particular, the detailed characterization of such a material has a great relevance because of its application in the healing process of the osteochondral defect that consists of a damage of cartilage and injury of the adjacent subchondral bone, significantly compromising millions of patient's quality of life. Two different techniques exploiting X-ray radiation, with table-top setups, are used: microtomography (micro-CT) and microdiffraction. Micro-CT characterizes the microstructure in the three dimensions at the micrometer scale spatial resolution, whereas microdiffraction provides combined structural/morphological information at the atomic and nanoscale, in two dimensional microscopy images with a hundred micrometer spatial resolution. The combination of these two techniques allowed an appropriate structural characterization for the purpose of validating the engineering approach used for the realization of the hydroxyapatite gradient across the scaffold, with properties close to the natural model.

In this paper, a method to synthesize anatase TiO2 nanorods by hydrolysis of titanium(IV) isopropoxide(TTIP) in the presence of benzyl alcohol and acetic acid at 210 °C was tested. The novelty of the presentapproach relies on the evaluation of the shape-controlled synthesis of anatase TiO2 nanocrystals via amicrowave-solvothermal method in 45 min. The different TiO2 nanocrystals were obtained by tuningthe TTIP/acetic acid ratio under optimized synthetic conditions and were characterized in detail by X-raydiffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), micro Raman(together with microphotoluminescence) and FT-IR spectroscopies. The acetic acid coordinated on thenanocrystal surface was removed by the reduction of its carboxyl group via a "super-hydride reaction",and the photocatalytic activity of bare TiO2 nanocrystals, under visible light irradiation, was alsoevaluated: the best performing TiO2 anatase nanocrystals exhibited a discrete photoactivity, completelydegrading Rhodamine B solution in five hours.

Drop casting of highly concentrated solutions of nanorods in high boiling point solvents, followed by slow solvent evaporation, leads to the formation of crack-free multilayers of vertically aligned rods in square centimeter areas.

Water soluble fibers of PEGylated tetra-phenylalanine (F4), chemically modified at the N-terminus with the DOTA chelating agent, have been proposed as innovative contrast agent (CA) in Magnetic Resonance Imaging (MRI) upon complexation of the gadolinium ion. An in-depth structural characterization of PEGylated F4-fibers, in presence (DOTA-L-6-F4) and in absence of DOTA (L-6-F4), is reported in solution and at the solid state, by a multiplicity of techniques including CD, FTIR, NMR, DLS, WAXS and SAXS. This study aims to better understand how the aggregation process influences the performance of nanostructures as MRI CAs. Critical aggregation concentrations for L-6-F4 (43 mu M) and DOTA-L-6-F4 (75 mu M) indicate that self-aggregation process occurs in the same concentration range, independently of the presence of the CA. The driving force for the aggregation is the pi-stacking between the side chains of the aromatic framework. CD, FTIR and WAXS measurements indicate an antiparallel beta-sheet organization of the monomers in the resulting fibers. Moreover, WAXS and FTIR experiments point out that in solution the nanomaterials retain the same morphology and monomer organizations of the solid state, although the addition of the DOTA chelating agent affects the size and the degree of order of the fibers.

Here the synthesis of distinct monomodal and bimodal PbS nanocrystal (NC) populations, with narrow size-distribution, is reported. The ability to achieve careful control of NC size and size distribution allowed the preparation, in one single synthetic step, of two distinct populations of PbS NCs, with tuneable size ratio. The NC growth was carefully studied in order to gain insight into the mechanism underlying the formation of the mono and bimodal PbS NC families. The synthesized PbS NCs were structurally and chemically characterized, and subsequently used as building blocks for fabricating solid crystal assemblies by solvent evaporation. In particular the role played by different parameters, namely NC size and concentration, dispersing solvent and substrate, on crystallinity, geometry and structure of the obtained solids was systematically investigated. Interestingly the assembly of bimodal PbS NC samples leads to the formation of diverse superlattice structures, with a final geometry dependent on the NC size and the size ratio in the bimodal population. The synthetic procedure was then ultimately responsible of the superlattice structures, through the control of the PbS NC size and size ratio in the bimodal population.

We demonstrate that it is possible to convert CdSe nanocrystals of a given size, shape (either spherical or rod shaped), and crystal structure (either hexagonal wurtzite, i.e., hexagonal close packed (hcp), or cubic sphalerite, i.e., face-centered cubic (fcc)), into ZnSe nanocrystals that preserve all these characteristics of the starting particles (i.e., size, shape, and crystal structure), via a sequence of two cation exchange reactions, namely, Cd(2+) -> Cu(+) -> Zn(2+). When starting from hexagonal wurtzite CdSe nanocrystals, the exchange of Cd(2+) with Cu(+) yields Cu(2)Se nanocrystals in a metastable hexagonal phase, of which we could follow the transformation to the more stable fcc phase for a single nanorod, under the electron microscope. Remarkably, these metastable hcp Cu(2)Se nanocrystals can be converted in solution into ZnSe nanocrystals, which yields ZnSe nanocrystals in a pure hcp phase.

All biomaterials initiate a tissue response when implanted in living tissues. Ultimately this reaction causes fibrous encapsulation and hence isolation of the material, leading to failure of the intended therapeutic effect of the implant. There has been extensive bioengineering research aimed at overcoming or delaying the onset of encapsulation. Nanotechnology has the potential to address this problem by virtue of the ability of some nanomaterials to modulate interactions with cells, thereby inducing specific biological responses to implanted foreign materials. To this effect in the present study, we have characterised the growth of fibroblasts on nano-structured sheets constituted by BaTiO3, a material extensively used in biomedical applications. We found that sheets of vertically aligned BaTiO3 nanotubes inhibit cell cycle progression - without impairing cell viability - of NIH-3T3 fibroblast cells. We postulate that the 3D organization of the material surface acts by increasing the availability of adhesion sites, promoting cell attachment and inhibition of cell proliferation. This finding could be of relevance for biomedical applications designed to prevent or minimize fibrous encasement by uncontrolled proliferation of fibroblastic cells with loss of material-tissue interface underpinning long-term function of implants.

OFETs based on new solution-processed ester functionalized 9,10-ter-anthrylene-ethynylenes show a mobility increase of four orders of magnitude, leading to mobilities as high as 4.9 x 10(-2) cm(2) V(-1) s(-1) if the deposited film is annealed before contact deposition. The behavior is ascribed to an increase in film order at the dielectric/semiconductor interface as revealed by X-ray studies.

Titania anatase nanocrystals were prepared by solgel solvothermal synthesis in oleic acid at 2508C, and modified by co-reaction with Mo chloroalkoxide, aimed at investigatingthe effects on gas-sensing properties induced by tailored nanocrystals surface modification with ultra-thin layers of MoOx species. For the lowest Mo concentration, only anatasenanocrystals were obtained, surface modified by a disordered ultra-thin layer of mainly octahedral MoVI oxide species.For larger Mo concentrations, early MoO2 phase segregation occurred. Upon heat treatment up to 5008C, the sample with the lowest Mo concentration did not featureany Mo oxide phase segregation, and the surface Mo layer was converted to dense octahedral MoVI oxide. At larger Mo concentrations all segregated MoO2 was converted to MoO3. The two different materials typologies, depending on the Mo concentration, were used for processing gas-sensing devicesand tested toward acetone and carbon monoxide, which gave a greatly enhanced response, for all Mo concentrations, to acetone (two orders of magnitude) and carbonmonoxide with respect to pure TiO2. For the lowest Mo concentration, dye-sensitized solar cells were also prepared to investigate the influence of anatase surface modification onthe electrical transport properties, which showed that the charge transport mainly occurred in the ultra-thin MoOx surface layer.

We have developed a general X-ray powder diffraction (XPD) methodology for the simultaneous structural and compositional characterization of inorganic nanomaterials. The approach is validated on colloidal tungsten oxide nanocrystals (WO3-x NCs), as a model polymorphic nanoscale material system. Rod-shaped WO3-x NCs with different crystal structure and stoichiometry are comparatively investigated under an inert atmosphere and after prolonged air exposure. An initial structural model for the as-synthesized NCs is preliminarily identified by means of Rietveld analysis against several reference crystal phases, followed by atomic pair distribution function (PDF) refinement of the best-matching candidates (static analysis). Subtle stoichiometry deviations from the corresponding bulk standards are revealed. NCs exposed to air at room temperature are monitored by XPD measurements at scheduled time intervals. The static PDF analysis is complemented with an investigation into the evolution of the WO3-x NC structure, performed by applying the modulation enhanced diffraction technique to the whole time series of XPD profiles (dynamical analysis). Prolonged contact with ambient air is found to cause an appreciable increase in the static disorder of the O atoms in the WO3-x NC lattice, rather than a variation in stoichiometry. The time behavior of such structural change is identified on the basis of multivariate analysis.

Peptides containing aromatic residues are known to give spontaneous phenomena of supramolecular organization into ordered nanostructures (NSs). Here we studied the structural behavior and the optoelectronic properties of new biocompatible materials obtained by self-assembling of a series of hexaphenylalanines (F6) modified at the N-terminus with a PEG chain of different length. PEG12-F6, PEG18-F6 and PEG24-F6 peptides were synthesized by coupling sequentially two, three or four units of amino-carboxy PEG6 blocks, each one containing six ethoxylic repetitions. Changes in length and composition of the PEG chain were found able to modulate the structural organization of phenylalanine based nanostructures. An increase in the self-aggregation tendency with longer PEG is observed; while, independently from PEG length, the peptide NSs display cross-beta like secondary structure with an antiparallel beta-strand arrangement. WAXS/GIWAXS diffraction patterns indicate a progressive decrease of the fiber order along the series. All the PEG-F6 derivatives present blue photoluminescent (PL) emission at 460 nm, while the adduct with longest PEG (PEG24-F6) shows an additional green emission at 530 nm.

Organic field-effect transistors including a functional biorecognition interlayer, sandwiched between the dielectric and the organic semiconductor layers, have been recently proposed as ultrasensitive label-free biosensors capable to detect a target molecule in the low pM concentration range. The morphology and the structure of the stacked bilayer formed by the protein biointerlayer and the overlying organic semiconductor is here investigated for different protein deposition methods. X-ray scattering techniques and scanning electron microscopy allow us to gather key relevant information on the interface structure and to assess target analyte molecules capability to percolate through the semiconducting layer reaching the protein deposit lying underneath. Correlations between the structural and morphological data and the device analytical performances are established allowing us to gather relevant details on the sensing mechanism and further improving sensor performances, in particular in terms of sensitivity and selectivity. © 2014 American Chemical Society.

Over the years, a large number of multidisciplinary investigations has unveiled that the self-assembly of short peptides and even of individual amino acids can generate a variety of different biomaterials. In this framework, we have recently reported that polyethylene glycol (PEG) conjugates of short homopeptides, containing aromatic amino acids such as phenylalanine (Phe, F) and naphthylalanine (Nal), are able to form elongated fibrillary aggregates having interesting chemical and physical properties. We here extend these analyses characterizing the self-assembling propensity of PEG(6)-W4, a PEG adduct of the tetra-tryptophan (W4) sequence. A comprehensive structural characterization of PEG(6)-W4 was obtained, both in solution and at the solid state, through the combination of spectroscopic, microscopic, X-ray scattering and computational techniques. Collectively, these studies demonstrate that this peptide is able to self-assemble in fibrillary networks characterized by a cross -structure spine. The present findings clearly demonstrate that aromatic residues display a general propensity to induce self-aggregation phenomenon, despite the significant differences in the physicochemical properties of their side chains.

Three-dimensional binary superlattices were obtained by self-assembly of PbS nanocrystals (NCs) of size <= 4 nm, synthesized by colloidal chemistry routes and characterized by two distinct and narrow size distributions. The resulting binary superstructures have been imaged by small- and wide-angle X-ray diffraction (XRD), and by transmission electron microscopy (TEM). The combined use of such investigation techniques allowed retrieval of crystalline structure, size, and shape of the PbS NCs, along with their spatial arrangement in the 3D architecture. A detailed analysis of the wide-angle XRD data, based on the Debye approach, demonstrated an elongated shape of NCs even smaller than 2 nm and provided a lower limit for the effective NC size, to be compared with results from TEM. The careful interpretation of small-angle XRD data demonstrated the ordered arrangement of NCs perpendicularly to the substrate plane and, together with TEM observations, allowed retrieval of the 3D structure of the assembly. Moreover small-angle XRD is shown to contain peculiar features related to the size distribution of the NCs and the degree of order in the assembly. Such a highly detailed structural analysis, averaged over large volumes of the investigated material, can hardly be obtained even by sophisticated high-resolution TEM.

Ribosome biogenesis is closely linked to the cell growth and proliferation. Dysregulation of this process causes several diseases collectively known as ribosomopathies. One of them is the Shwachman-Diamond Syndrome, and the SBDS protein mutated in this disease participates with EFL1 in the cytoplasmic maturation of the 60S subunit. Recently, we have shown that the interaction of EFL1 with SBDS resulted in a decrease of the Michaelis-Menten constant (KM) for GTP and thus SBDS acts as a GEF for EFL1 (1). Subsequent studies demonstrated that SBDS greatly debilitates the interaction of EFL1 with GDP without altering that for GTP. The interaction of EFL1 alone or in complex with SBDS to guanine nucleotides is followed by a conformational rearrangement. Understanding the molecular strategy used by SBDS to disrupt the binding of EFL1 for GDP and the associated conformational changes will be key to understand their mode of action and alterations occurring in the disease. The structure of the GTPase EFL1 is not known and its crystallization has been unsuccessful at least in our hands. In this study, we aim to show the conformational changes resulting from the interactions between EFL1 and its binding partners, the SBDS protein and the guanine nucleotides using SAXS technique (2, 3). SAXS will provide structural information of the proteins and their conformational changes (4). For the SAXS data analysis we have built models of EFL1 using by EF-2 as homology template and of SBDS using the crystal structures of the archaea orthologues.

The effects of pulsed microwave discharges on the deposition and properties of a set of polycrystalline diamond films are investigated by varying the duty cycle at a fixed pulse frequency and keeping constant the peak microwave power at 1250 W, the substrate temperature and the final film thickness. The deposition polycrystalline diamond films obtained from highly diluted CH(4) (1% CH(4) in H(2)) gas mixtures was monitored by pyrometric interferometry technique. This analysis evidences that, in order to obtain the same thickness, the nucleation/deposition times and the process rates increase and decrease, respectively, by decreasing the pulse duration. Moreover, the influence of the variations of duty cycle on the deposition rates, the surface morphology, the optical properties (refractive index and extinction coefficient) and the crystallite orientations of the polycrystalline diamond films is investigated.

Herein, we report a colloidal wet-chemical approach enabling control on dopant concentration and location in a nanocrystal host lattice. Growth-doping and nucleation-doping, driven by primary and tertiary amines, respectively, were identified as predominant doping mechanisms responsible for the introduction of nitrogen impurities in interstitial and substitutional sites in highly branched rutile TiO2 nanostructures. High-resolution X-ray photoelectron spectroscopy was used to distinguish the two nitrogen occupational lattice sites and, in combination with UVvis absorption spectroscopy, to investigate the impact of the nitrogen impurities on the optoelectronic properties. The implementation of the nitrogen-doped titania nanostructures in photoelectrodes for water oxidation suggests that these atomically defined building blocks can function as a platform to investigate the impact of the nitrogen occupational sites on the photocatalytic properties. By deliberately choosing precursors and reaction conditions, instead of relying on the most common high temperature annealing of preformed metal oxide in ammonia, we emphasize the importance of understanding the chemistry behind doping to achieve an unprecedented level of control on effective dopant introduction and, therefore, property tunability.

SUNBIM (Supramolecular & SUbmolecular Nano & Bio Materials X-ray IMaging Project) is a suite of integrated programs developed, in collaboration with Rigaku Innovative Technologies, to treat Small and Wide Angle X-ray Scattering data, collected either in transmission geometry (SAXS/WAXS) or in reflection geometry (GISAXS/GIWAXS). In addition, a specific routine to collect and analyze data in SAXS scanning transmission microscopy has been developed as additional tool to investigate tissues or material science samples through a focused X-ray beam which is used to raster scan a specimen while acquiring SAXS scattering patterns with a 2D detector. Indeed, a first-generation-synchrotron-class FrE+ SuperBright Rigaku microsource, coupled to a three pinhole S-MAX3000 camera, was recently installed at the X-ray MicroImaging Laboratory (XMI-L@b) and used with success in SAXS/WAXS/GISAXS/GIWAXS experiments (De Caro et al, 2012; 2013)and for SAXS scanning microscopy (Altamura et al, 2012; Giannini et al, 2013).

SUNBIM (supramolecular and submolecular nano- and biomaterials X-rayimaging) is a suite of integrated programs which, through a user-friendlygraphical user interface, are optimized to perform the following: (i) q-scalecalibration and two-dimensional ! one-dimensional folding on small- andwide-angle X-ray scattering (SAXS/WAXS) and grazing-incidence SAXS/WAXS (GISAXS/GIWAXS) data, also including possible eccentricity correctionsfor WAXS/GIWAXS data; (ii) background evaluation and subtraction,denoising, and deconvolution of the primary beam angular divergence onSAXS/GISAXS profiles; (iii) indexing of two-dimensional GISAXS frames andextraction of one-dimensional GISAXS profiles along specific cuts; (iv) scanningmicroscopy in absorption and SAXS contrast. The latter includes collection oftransmission and SAXS data, respectively, in a mesh across a mm2 area,organization of the as-collected data into a single composite image oftransmission values or two-dimensional SAXS frames, analysis of the composeddata to derive the absorption map and/or the spatial distribution, andorientation of nanoscale structures over the scanned area.

Nanocrystalline diamond (NCD) coatings with thickness of about 3 um were grown on silicon substrates at four deposition temperatures ranging from 653 to 884 degrees C in CH4/H2/Ar microwave plasmas. The morphology, structure, chemical composition and mechanical and surface properties were studied by means of Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), Raman spectroscopy, nanoindentation and Water Contact Angle (WCA) techniques. The different deposition temperatures used enabled to modulate the chemical, structural and mechanical NCD properties, in particular the grain size and the shape. The characterization measurements revealed a relatively smooth surface morphology with a variable grain size, which affected the incorporated hydrogen amount and the sp(2) carbon content, and, as a consequence, the mechanical properties. Specifically, the hydrogen content decreased by increasing the grain size, whereas the sp(2) carbon content increased. The highest values of hardness (121 +/- 25 GPa) and elastic modulus (1036 +/- 163 GPa) were achieved in NCD film grown at the lowest value of deposition temperature, which favored the formation of elongated nanocrystallites characterized by improved hydrophobic surface properties. (C) 2014 Elsevier B.V. All rights reserved.

Drops of exosome dispersions from healthy epithelial colon cell line and colorectal cancer cells were dried on a superhydrophobic PMMA substrate. The residues were studied by small- and wide-angle X-ray scattering using both a synchrotron radiation micrometric beam and a high-flux table-top X-ray source. Structural differences between healthy and cancerous cells were detected in the lamellar lattices of the exosome macro-aggregates.

Suitable post-synthesis surface modification of lead-chalcogenide quantum dots (QDs) is crucial to enable their integration in photovoltaic devices. We have developed a solution-phase ligand exchange strategy that exploits arenethiolate anions to replace the pristine oleate ligands on PbS QDs, while preserving the long-term colloidal stability of QDs and allowing their solution-based processability into photoconductive thin-films. Complete QD surface modification is demonstrated by IR spectroscopy analysis, whereas UV-Vis-NIR Absorption Spectroscopy provides quantitative evaluation of stoichiometry and thermodynamic stability of the resulting system. Arenethiolate ligands permit to reduce the inter-particle distance in PbS QD solids, leading to a drastic improvement of the photoinduced charge transport properties. Therefore, smooth dense-packed thin-films of arenethiolate-capped PbS QDs obtained via a single solution-processing step are integrated in heterojunction solar cells: such devices generate remarkable photocurrent densities (14 mA cm(-2)) and overall efficiencies (1.85%), which are outstanding for a single PbS QD layer. Solution-phase surface modification of QDs thus represents an effective intermediate step towards low-cost processing for all-inorganic and hybrid organic/inorganic QD-based photovoltaics.

Phase separation of a polymer solution exhibits a peculiar behavior when induced in a nanoconfinement. The energetic constraints introduce additional interactions between the polymer segments that reduce the number of available configurations. In our work, this effect is exploited in a one-step strategy called nanoconfined-Thermally Induced Phase Separation (nc-TIPS) to promote the crystallization of polymer chains into nanocapsular structures of controlled size and shell thickness. This is accomplished by performing a quench step of a low-concentrated PLLA-dioxane-water solution included in emulsions of mean droplet size < 500 nm acting as nanodomains. The control of nanoconfinement conditions enables not only the production of nanocapsules with a minimum mean particle diameter of 70 nm but also the tunability of shell thickness and its crystallinity degree. The specific properties of the developed nanocapsular architectures have important implications on release mechanism and loading capability of hydrophilic and lipophilic payload compounds.

The present investigation reported the synthesis of ultrafine anatase titanium dioxide (TiO2) nanocrystals using titanium isopropoxide (TTIP) as precursor in presence of benzyl alcohol as solvent and glucose as capping agent via a microwave-solvothermal method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption, micro Raman and Fourier transform infrared spectroscopies (FT-IR). From this preparation method it was demonstrated that the obtainable TiO2 nanocrystals were less than 10 nm in mean size, mainly in anatase phase, presenting also a mesoporous structure. The use of glucose as capping agent added in the reaction system played a role in the anisotropic growth of the TiO2 nanocrystals, as evidenced by XRD domain size analysis and promoted an increase of the specific surface area.

XTOP 2018 - the 14th Biennial Conference on High-Resolution X-Ray Diffraction and ImagingBari, 3rd -7th September 2018TABLE-TOP SCANNING SAXS/WAXS MICROSCOPY OF ENGINEERED NANO/BIO-MATERIALSD. Altamura1,*, S.G. Pastore1, D. Siliqi1, M. Ladisa1, F. Scattarella1, A. Terzi1, and C. Giannini11 CNR-Istituto di Cristallografia, Via Amendola 122/O, 70126 Bari, Italy*e-mail: (davide.altamura@ic.cnr.it)INTRODUCTION: Simultaneous SAXS/WAXS data collection allows to directly relate atomic and nano- scale structures at each point on the sample. Synchrotron beamlines typically exploit an off-axis detector for WAXS, although this prevents the collection of diffraction rings over the full azimuthal range, or scanning is performed twice to collect the full scattering signal at small (SAXS) and wide (WAXS) angles. Despite the excellent data quality, a possible drawback can be some information loss and/or mismatch between SAXS and WAXS maps due to sample structural evolution (spontaneous, due to drying, radiation damage, drifts). A different approach, also available in table-top facilities, exploits an image plate detector with central hole, to collect the average 2D WAXS signal along with a spatially resolved SAXS map, and/or single SAXS/WAXS patterns from selected sample points.EXPERIMENTAL: A Rigaku synchrotron-class micro-source, coupled to a SAXS/WAXS camera, allows for double length scale diffraction microscopy with 70?200 ?m spatial resolution1.RESULTS AND DISCUSSION: Even though a scattering component from sample local structure can be partially smeared out in the integrated average, the spatially resolved SAXS/Absorption map can help in discriminating and localizing micro- and nano-scale components (e.g. CaS and HA, respectively, in the Figure), through the following simultaneous SAXS/WAXS signal collection from selected regions of interest. Once the correspondence of SAXS/WAXS features is assessed, the 2D SAXS/Absorption map can be used for qualitative structural mapping, quantitative estimation of concentration gradients (e.g. HA nanocrystals across the scaffold in the Figure)1, or statistical quantitative information can be extracted by averaging the normalized SAXS intensity in selected q-ranges, for comparative studies on nanoparticle abundance (e.g. oil nanodroplets in films made from emulsions)2, among others.CONCLUSIONS:The simultaneous SAXS/WAXS-integrated full pattern collection allows for double length scale description of the real-time status of the sample, with 2D spatial resolution, without loss of intensity or possibly information in case of preferred orientations, and is feasible with laboratory equipment.REFERENCES:1. D. Altamura, S. G. Pastore, M. G. Raucci, D. Siliqi, F. De Pascalis, M. Nacucchi, L. Ambrosio, and C. Giannini. ACS Appl. Mater. Interfaces (2016), 8, 8728-8736.2. Juan M. Montes de Oca-Ávalosa, D. Altamura, Roberto J. Candal, F. Scattarella, D. Siliqi, C. Giannini, M. Lidia Herrera. Relationship between nano/mi

We investigate the relationship between structural and optical properties of organo-lead mixed halide perovskite films as a function of the crystallization mechanism. For methylammonium lead tri-iodide, the organic cations rearrange within the inorganic cage, moving from crystals grown in a mesoporous scaffold to larger, oriented crystals grown on a flat substrate. This reduces the strain felt by the bonds forming the cage and affects the motion of the organic cation in it, influencing the electronic transition at the onset of the optical absorption spectrum of the semiconductor. Moreover, we demonstrate that in mixed-halide perovskite, though Cl- ions are not present in a detectable concentration in the unit cell, they drive the crystallization dynamics. This induces a preferential order during crystallization, from a molecular, i.e., organic-inorganic moieties arrangement, to a nano-mesoscopic level, i.e., larger crystals with anisotropic shape. Finally, we show that while Cl is mainly expelled from flat films made of large crystals, in the presence of an oxide mesoporous scaffold they are partially retained in the composite.

The progress of tomographic coherent diffractive imaging with hard X-rays at the ID10 beamline of the European Synchrotron Radiation Facility is presented. The performance of the instrument is demonstrated by imaging a cluster of Fe2P magnetic nanorods at 59 nm 3D resolution by phasing a diffraction volume measured at 8 keV photon energy. The result obtained shows progress in three-dimensional imaging of non-crystalline samples in air with hard X-rays.

Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red andnear-infrared spectral regions, are of great interest for optoelectronic and bio-imagingapplications. The growth of an inorganic passivation layer on nanocrystal surfaces is a commonstrategy to improve their chemical and optical stability and their photoluminescence quantumyield. In particular, cation exchange is a suitable approach for shell growth at the expense of thenanocrystal core size. Here, the cation exchange process is used to promote the formation of aCdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blueshifting their optical spectra and yielding luminescent and stable nanostructures emitting in therange of 700-850 nm. Structural, morphological and compositional investigation confirms thenanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystallinephase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of apassivation layer with a decrease of the PbS core size, as inferred by the blue-shift of theexcitonic peaks. The surface passivation strongly increases the photoluminescence intensity andthe excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidationover time. Thanks to their absorption and emission spectral range and the slow recombinationdynamics, such highly luminescent nano-objects can find interesting applications in sensitizedphotovoltaic cells and light-emitting devices.

The Turin Shroud is traditionally considered the burial cloth of Jesus Christ, but carbon-14 analysis indicated a medieval date. Here, a digital restoring of the hands' region of the Turin Shroud image has allowed to visualize anatomic details never seen before: the scrotum and part of the right hand's thumb. Additionally, the unnatural position of the right hand's thumb, adjacent to the palm of the hand, positioned below it and, consequently, almost fully hidden except for its protruding end, seems to denote a stress, which could be consequent to crucifixion. These results shed new light on the long-lasting scientific debate about the authenticity of the relic since the absence of the thumbs has been considered as one of the most important indirect proof that the Turin Shroud wrapped the body of a man who was crucified alive. (C) 2016 Elsevier Masson SAS. All rights reserved.

Au nanoparticles (NPs) self-assembled by means of a simple solvent evaporation strategy in a two-dimensional (2D) superlattice with a highly controlled geometry and extending over micrometers squared when drop cast onto a suitably functionalized silicon substrate. The assembly procedure was defined by carefully monitoring experimental parameters, namely, dispersing solvent, deposition temperature, Au NP concentration, and chemistry of supporting substrate. The investigated parameters were demonstrated to play a significant role on the delicate energetic balance of the mutual NPs as well as NP-substrate interactions, ultimately directing the NP assembly. Remarkably, substrate surface chemistry revealed to be decisive to control the extent of the organization. Scanning electron microscopy demonstrated that the 2D superlattice extends uniformly over hundreds of square micrometers. Grazing-incidence small-angle X-ray scattering investigation validated the Au NP organization in crystalline domains and confirmed the role played by the surface chemistry of the substrate onto the 2D lattice assembly. Finally, preliminary spectroscopic ellipsometry investigation allowed extraction of optical constants of NP assemblies. The localized surface plasmon resonance modes of the NP assemblies were studied through a combined analysis of reflection, transmission, and ellipsometric data that demonstrated that the plasmonic properties of the Au NP assemblies strongly depend on the substrate, which was found to influence NP ordering and near-field interactions between NPs. © 2014 American Chemical Society.

The peculiar architecture of a novel class of anisotropic TiO2(B) nanocrystals, which were synthesized by an surfactant-assisted nonaqueous sol-gel route, was profitably exploited to fabricate highly efficient mesoporous electrodes for Li storage. These electrodes are composed of a continuous spongy network of interconnected nanoscale units with a rod-shaped profile that terminates into one or two bulgelike or branch-shaped apexes spanning areas of about 5 x 10 nm(2). This architecture transcribes into a superior cycling performance (a charge capacitance of 222 mAh g(-1) was achieved by a carbon-free TiO2(B)-nanorods-based electrode vs 110 mAh g(-1) exhibited by a comparable TiO2-anatase electrode) and good chemical stability (more than 90% of the initial capacity remains after 100 charging/discharging cycles). Their outstanding lithiation/delithiation capabilities were also exploited to fabricate electrochromic devices that revealed an excellent coloration efficiency (130 cm(2) C-1 at 800 nm) upon the application of 1.5 V as well as an extremely fast electrochromic switching (coloration time similar to 5 s).

The detailed action mechanism of volatile general anesthetics is still unknown despite their effect has been clinically exploited for more than a century. Long ago it was also assessed that the potency of an anesthetic molecule well correlates with its lipophilicity and phospholipids were eventually identified as mediators. As yet, the direct effect of volatile anesthetics at physiological relevant concentrations on membranes is still under scrutiny. Organic field-effect transistors (OFETs) integrating a phospholipid (PL) functional bio inter-layer (FBI) are here proposed for the electronic detection of archetypal volatile anesthetic molecules such as diethyl ether and halothane. This technology allows to directly interface a PL layer to an electronic transistor channel, and directly probe subtle changes occurring in the bio-layer. Repeatable responses of PL FBI-OFET to anesthetics are produced in a concentration range that reaches few percent, namely the clinically relevant regime. The PL FBI-OFET is also shown to deliver a comparably weaker response to a non-anesthetic volatile molecule such as acetone. © 2012 Elsevier B.V.

During recent decades innovative nanomaterials have been extensively studied, aiming at both investigating the structure-property relationship and discovering new properties, in order to achieve relevant improvements in current state-of-the art materials. Lately, controlled growth and/or assembly of nanostructures into hierarchical and complex architectures have played a key role in engineering novel functionalized materials. Since the structural characterization of such materials is a fundamental step, here we discuss X-ray scattering/diffraction techniques to analyze inorganic nanomaterials under different conditions: dispersed in solutions, dried in powders, embedded in matrix, and deposited onto surfaces or underneath them.

A first-generation-synchrotron-class X-ray laboratory microsource, coupled to a three-pinhole camera, is presented. It allows (i) small- and wide-angle X-ray scattering images to be acquired simultaneously, and (ii) scanning small- and wide-angle X-ray scattering microscopy to be carried out. As representative applications, the structural complexity of a biological natural material (human bone biopsy) and of a metamaterial (colloidal nanocrystal assembly) are inspected at different length scales, studying the atomic/molecular ordering by (grazing-incidence) wide-angle X-ray scattering and the morphological/structural conformation by (grazing-incidence) small-angle X-ray scattering. In particular, the grazing-incidence measurement geometries are needed for inspecting materials lying on top of surfaces or buried underneath surfaces.