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A series of potassium-promoted spinels (Mn, Fe, Co) were prepared with various K promoter locations: on the surface (surface promotion) or in the bulk (formation of new layered and tunneled nanostructures via solid state reaction). All prepared samples were characterized by means of X-ray diffraction, Raman spectroscopy, X-ray fluorescence and N-BET specific surface area analysis. Catalytic activity in soot combustion in different reaction conditions was investigated ( tight contact, loose contact, loose contact with NO addition). It was shown that in all cases the nanostructuration is more effective than the surface promotion, with the layered structures of KCoO, KMnO being the most catalytically active phases, lowering the soot combustion down to 250 °C. The difference in activity between tight and loose contacts can be bridged in the presence of NO due to its transformation into NO, which acts as the oxygen carrier from the catalyst surface into soot particles, eliminating the soot-catalyst contact difference. [ABSTRACT FROM AUTHOR]

Pure tysonite La 0.95 Ba 0.05 F 2.95 is nanostructured by using the ball-milling technique. Size and pollution rate are minimized using the statistical method of Design of Experiment. The nanocrystalline powders are studied by X-ray and TEM analyses and by 19 F solid state NMR and impedance spectroscopies. Specific surface area and F/OH substitution rate are estimated by BET measurements and thermal analysis (TGA-MS), respectively. Fluorine environments and mobilities are discussed on the basis of 19 F solid state NMR data, both prior and after thermal treatment. The ionic conductivity, evaluated from sintered pellets, is compared at different thermal treatment temperatures. Thermal treatment tends to reduce microstrains up to 500 °C and to increase the grain size above this temperature. Optimal conductivity is obtained for a thermal treatment from 700 °C and no significant improvement of the conductivity by nanostructuration is observed. [ABSTRACT FROM AUTHOR]

In competitive thermoelectric devices for energy conversion and generation, high-efficiency materials of both n-type and p-type are required. For this, BiTe-based alloys have the best thermoelectric properties in room temperature applications. Partial replacement of tellurium by selenium is expected to introduce new donor states in the band gap, which would alter electrical conductivity and thermopower. We report on the preparation of n-type Bi(TeSe) solid solutions by a straightforward arc-melting technique, yielding nanostructured polycrystalline pellets. X-ray and neutron powder diffraction was used to assess Se inclusion, also indicating that the interactions between quintuple layers constituting this material are weakened upon Se doping, while the covalency of intralayer bonds is augmented. Moreover, scanning electron microscopy shows large surfaces perpendicular to the c crystallographic axis assembled as stacked sheets. Grain boundaries related to this 2D nanostructuration affect the thermal conductivity reducing it below 0.8 WmK at room temperature. Furthermore, Se doping increases the absolute Seebeck coefficient up to −140 μV K at 400 K, which is also beneficial for improved thermoelectric efficiency. [ABSTRACT FROM AUTHOR]

SnSe has been recently reported as a promising and highly efficient thermoelectric intermetallic alloy. The present material has been prepared by arc melting, as mechanically robust pellets, consisting of highly oriented polycrystals. The evolution of its orthorhombic GeS-type structure (space group Pnma) and phase transition to TlI-type structure (space group Cmcm) at high temperature has been studied in situ by neutron powder diffraction (NPD) in the temperature range 295-873 K. This transition has been identified by differential scanning calorimetry measurements, yielding sharp peaks at 795 K. In addition, thermal transport properties were measured in a similar temperature range, and large Seebeck coefficients, as high as 1050 µV K−1 at 625 K, were found. The analysis from NPD data demonstrates an almost perfect stoichiometry, Sn0.998(8)Se, that does not evolve with temperature, and a progressive decrease of the anharmonicity of the chemical bonds upon entering the domain of the Cmcm structure. [ABSTRACT FROM AUTHOR]

In this paper, we report on an improved enhancement of the surface-enhanced Raman scattering (SERS) effect. Such improvement is obtained by using a continuous gold film (underlayer), which is added below an array of gold nanostructures. Two types of nanostructures were studied to validate our results: regular disk arrays with two diameters (110 and 210 nm) and lines with a width of 110 nm, all on a gold film of 30 nm thick. A supplementary gain of one order of magnitude on the SERS enhancement factor (EF) was experimentally demonstrated for several excitation wavelengths: 633, 660, and 785 nm. With such SERS substrates, EFs of 10 are observed for thiophenol detection. This opens the way towards routine and reliable detection of molecules at low concentration. [ABSTRACT FROM AUTHOR]

Thermoelectric materials constitute an alternative source of sustainable energy, harvested from waste heat. BiTe is the most utilized thermoelectric alloy. We show that it can be readily prepared in nanostructured form by arc-melting synthesis, yielding mechanically robust pellets of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanning electron microscopy (SEM), and electronic and thermal transport measurements. A microscopic analysis from NPD data demonstrates a near-perfect stoichiometry of BiTe and a fair amount of anharmonicity of the chemical bonds. The as-grown material presents a metallic behavior, showing a record-low resistivity at 320 K of 2 μΩ m, which is advantageous for its performance as a thermoelectric material. SEM analysis shows a stacking of nanosized sheets, each of them presumably single-crystalline, with large surfaces perpendicular to the c crystallographic axis. This nanostructuration notably affects the thermoelectric properties, involving many surface boundaries that are responsible for large phonon scattering factors, yielding a thermal conductivity as low as 1.2 W m K around room temperature. [ABSTRACT FROM AUTHOR]

General molecular engineering rules for the optimization of two-photon sensitive cages are presented and examples for nitrobenzyl, indole and nitrophenethyl platforms are highlighted. The efficiency of electron donor and acceptor groups in dipolar structures and the length of the conjugated system in the photolabile protecting group on two-photon uncaging efficiency will be discussed, as well as the emergence of symmetrical platform based onbis-electron donor or on quadrupolar architectures. We will then present our first results on the nano-structuration of donor-acceptor systems based on nitrophenetyl platform using diethyleneglycol or pentaerythritol cores. [ABSTRACT FROM AUTHOR]

In this work, we produce bulk nanostructured Mg 2 Si 0.4 Sn 0.6 thermoelectric materials made of nanograins with sizes below 200 nm and containing a fine distribution of Sn-rich nanoparticles. These materials are obtained by the mechanical alloying followed by spark plasma sintering. The microstructure and transport properties, and their evolutions upon aging, are investigated. A model is developed to capture the different contributions to the phonon scattering processes arising from the nano/microstructural parameters. The calculations show quantitative agreement with the temperature and the temporal dependence of the lattice thermal conductivity of the nanostructured Mg 2 Si 0.4 Sn 0.6 alloy. This work provides a general analytic approach for identifying the individual contributions of the microstructural parameters on the thermal conductivity which is a very important property controlling the performance of thermoelectric materials. [ABSTRACT FROM AUTHOR]

We report the design of a polyoxometalate-nanostructured immunosensor for benzo[a]pyrene (B[a]P) detection. The organic–inorganic hybrid polyoxometalate (POM) (NBu 4 ) 3 [PW 11 O 39 {(SiC 6 H 4 NH 2 ) 2 O}] carrying two amine functions was covalently attached to a functionalized gold substrate to achieve a nanometric organization of amine groups at its surface. Pyrenebutyric acid (PBA) was subsequently grafted to amine groups to create the sensing layer. The detection of B[a]P in the indirect competitive format was carried out using a monoclonal anti-B[a]P antibody whose binding to the immunoprobe was monitored with a quartz crystal microbalance with dissipation measurement (QCM-D). The performances of the POM-nanostructured biosensor were compared to a reference sensor constructed from a cysteamine self-assembled monolayer. QCM-D measurements displayed significant input from POM-nanostructuration. Both the accessibility of the analogue on the surface and the analytical performances were enhanced showing a promising effect of this strategy of nanostructuration for the biosensing of small molecules. [ABSTRACT FROM AUTHOR]

• CTA is partially miscible with VG or with PEO block in binary blends. • Morphology of binary blends strongly depends on both VG or EPE content. • Established morphologies diagram confirm that VG acted as nanostructuration agent. • The same morphologies is achieved adding VG and less EPE block copolymer. Polymer blends based on cellulose triacetate (CTA) modified with poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) triblock copolymer (PEO-PPO-PEO or EPE) and 1,1′‑diethyl-4,4′-bipyridinium dibromide (viologen or VG) were employed to obtain nanostructured micrometric films. 3VG/CTA binary blend showed worm-like structure, which was disrupted by the addition of 5 wt% of VG as a consequence of higher partial miscibility between blend components of 3VG/CTA blend. The competition between the self-assembly ability of EPE triblock copolymer and the formation of CTA crystalline lamellae was responsible for the morphology of EPE/CTA binary blends. In the ternary blends, CTA matrix was partially miscible with both VG and PEO block of EPE triblock copolymer. AFM proved that the addition of the 3 and 5 wt% of VG into had a similar effect on the final morphology of ternary systems contained 5 and 10 wt% of EPE triblock copolymer. The obtained results confirm not only self-organization ability of EPE block copolymer but also of VG. In ternary blends, VG acted as nanostructuration agent leading to similar morphology using less content of EPE block copolymer. The results provided from this investigation work allowed to build the morphologies diagram to design CTA based blends with tuneable morphologies obtained playing with VG and EPE content. [ABSTRACT FROM AUTHOR]

The low vapor pressure of explosives makes the gaseous detection challenging and drives even the particle detection. There is a need to provide easy portable systems, highly spreadable. A bio-inspired concept was developed to detect explosive vapors with unprecedent sensitivities. Vertically aligned TiO2 nanotubes were grown on a cantilever. The sensors successfully detected trinitrotoluene (TNT) and pentaerythritol tetranitrate (PETN) with a minimum threshold concentration down to 0.8 ppt. This work describes also the investigations undertaken to develop the characterization of explosives by nanocalorimetry, which is able to identify explosives in form of single particles. [ABSTRACT FROM AUTHOR]

Various ruthenium dioxide nanostructures were grown locally by the oxidation of ruthenium samples with an Ar-O 2 microwave micro-afterglow operated at atmospheric pressure. A special attention was paid to the distribution of the surface temperature of the sample which evolves between 530 K and 820 K. Whatever the treatment time, the temperature and the gas composition set within the studied ranges, a general nanostructure, made of lamellae separated by 20–50 nm, is found. When the temperature rises, localized nano-sea urchins, nanotubes with square sections, nano-needles, and more complex structures are found spread over the surface. Treated surfaces were characterized by different surface diagnostics (SEM, XRD, SIMS, etc.) Finally, a growth mechanism is proposed emphasizing the role of emerging defects and stress on the appearance of localized nanostructures. [ABSTRACT FROM AUTHOR]

Highlights: [•] Permanent superhydrophobic properties on injection-molded polypropylene substrates can be obtained by a simple dip-nanocoating process. [•] At Ti–OH surface relative concentrations higher than about 25%, the surface kept a superhydrophobic static state but lost its self-cleaning properties. [•] Precise tuning on the superhydrophobic dynamic component can be obtained by the control of the roughness together with the chemical surface composition of polar groups. [ABSTRACT FROM AUTHOR]

Abstract: Biofuel cells, and among them enzymatic biofuel cells, are expected to take part in a sustainable economy in a next future. The development of such biodevices requires significant improvements in terms of efficiency of enzyme immobilization at the electrodes, so as to enable direct electron transfer, and to increase and stabilize the current densities. Many works during the last years aimed at reaching higher current densities, thus power densities, while increasing the long term stability of the enzymatic bioelectrodes. Search for new enzymes, wild type or mutants, new entrapment procedures, but also new electrode architectures, have been targeted. This review focuses on the materials developed and involved during the last few years to meet these demands via nanostructuration of electrode interfaces. Discussion is essentially focused on cases where direct electron transfer between enzymes and electrochemical interfaces are involved. After having introduced the main reasons for the need of nanostructuration, the materials and methods that are newly developed are described. The consequences on improved performances for enzymatic bioelectrodes are discussed, and finally major challenges for future research are addressed. [Copyright &y& Elsevier]

[Display omitted] • Innovative nanostructurated device for thiol analysis. • The device was easy to use and allowed low molecular thiols quantification. • Thiols were quantified in simple and biological matrices. • Reduced glutathione concentration was successfully evaluated in rat plasma. Thiols are very important molecules in the biomedical field involved for example in redox homeostasis. Their detection and quantification remain difficult due to their poor stability (oxidation) linked to their strong reactivity towards other thiols (by the formation of S-S bonds) or other interfering molecules in the medium. Cellulose membranes with immobilized gold nanoparticles (AuNP) were developed to capture and quantify thiols in simple and complex matrices. This device was first optimized and characterized in terms of nanostructuration and thiol adsorption. N -Acetylcysteine (NAC) and reduced glutathione (GSH), chosen as model molecules, were filtered through the device demonstrating a maximal adsorption capacity of 270 and 60 nmol respectively. In a second step, the adsorbed species were subjected to ligand exchange using a more reactive thiol, dithiothreitol. The results showed release rates of approximately 90% for NAC and GSH. Finally, the amount of endogenous GSH in rat plasma was determined without any pretreatment. For the first time to our knowledge, a nanostructured device for the capture, selective and sensitive quantification of thiols is proposed. This device is easy to handle and overcomes matrix effects. Moreover, the very large concentration factor induced by this technology will be a valuable asset to decrease the quantification limits of analytical methods. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we report the synthesis and characterization of a new fluorescent ligand, ACRI-1 and its Co(II) coordination complex 1, [Co2(ACRI-1)2]. Complex 1 has been characterized by X-ray crystallography, magnetism and paramagnetic proton NMR. Nanostructuration of complex 1 has been achieved as monodisperse fluorescent nanoparticles and as thin layers on a HOPG surface. The thin layers have been characterized by AFM and GIXRD. [Copyright &y& Elsevier]

Abstract: Densities, viscosities and refractive index, as a function of temperature, and isobaric thermal expansion coefficient, were determined for 1-alkyl-3-methylimidazolium hexafluorophosphate, [CN−1C1im][PF6] (where N=5 to 10) series of ionic liquids. The density presents a regular decrease along the ionic liquid series, with no detectable alkyl chain length dependence of the thermal expansion coefficient. Both the refractive index and viscosity show a trend shift along the series around the [C6C1im][PF6] that could be associated to the impact of the change in the nanostructuration of the ionic liquids. The experimental results are compared with the analogous [CN−1C1im][NTf2] series and the effect of the anion is analyzed. The sphericity of the [PF6]− anion is reflected in the lower pre-exponential VTF parameter, Aη , and the higher viscosity of the [CN−1C1im][PF6], when compared with the [CN−1C1im][NTf2] series, is ruled by the higher energy barriers, which are related with stronger electrostatic interaction due to the low charge dispersion of the [PF6]−.anion. [Copyright &y& Elsevier]

On a flight back from Europe in 1993, I read a magazine article entitled ?The Power of Particles? (Lufthansa German Airlines 2/93, p. 54) and found it intriguing. I was working on high-voltage solid/gas interfaces and the concept of nanoscale seemed relevant to the phenomenology I was dealing with. In 1994 I also enjoyed and was inspired by John Lewis?s seminal paper on dielectricity at the nanometric scale (nanometric dielectric; IEEE Trans. DEIS 2004). [ABSTRACT FROM PUBLISHER]

Highlights: [•] Shear alignment of a block copolymer/epoxy thermosetting system is achieved. [•] Pre-shearing conditions play a key role in the orientation of the system. [•] Long-range order is investigated by TEM and SAXS. [ABSTRACT FROM AUTHOR]

Highlights: [•] A nanostructured polypyrrole powder is synthesized via a redox core–shell mechanism. [•] For that, a nanostructured MnO2 powder is used as oxidizing sacrificial template. [•] Reaction product is a pure and conducting PPy powder with a large specific area. [•] Its stoichiometry and production of soluble Mn2+ cations are clearly evidenced. [•] These new data will strengthen control in the synthesis of MnO2/PPy composite materials. [Copyright &y& Elsevier]

We propose the fabrication of nanostructured glassy carbon (GC) electrodes modified with horseradish peroxidase (HRP) for the detection of paracetamol. This was accomplished by inducing the nanostructuration of GC via the adsorption of polystyrene nanospheres (900 nm diameter) followed by electropolymerization of N-(10-azidodecyl)pyrrole. The nanospheres were then removed and nanostructured polypyrrole-GC was submitted to click reaction in presence of ethynyl-biotin that was further coupled to HRP-avidin. The electrode was then used to sense the electrochemical reduction of the enzymatically generated electroactive oxidized species of acetaminophen (NAPQI) in the presence of hydrogen peroxide. The nanostructured electrode with HRP exhibits a fast response towards NAPQI reduction and improved performances in terms of sensitivity and limit of detection compared to non structured electrode. [ABSTRACT FROM AUTHOR]

Modifications to the refractive indices of meso-structured organic-inorganic films caused by variations in the mole fraction of precursors in ethanolic solutions were investigated. The refractive indices were dependent on the mole fraction of CTMS (hexadecyltrimethoxysilane) and of the CTMS/TMOS (tetramethoxysilane) (1/1) mixture in ethanol. The dependency was determined to be nonlinear, and the phenomenon was attributed to self-assembly caused by the long alkyl groups (C) on the CTMS. Changes in the maximum decreasing rate of d/d values [(d/d)-for d/d estimation, the curves from Fig. 1 were associated with a polynomial; using a dedicated program, d/d was calculated; maximum values of d/d were taken into account and were included in Table 1)] were used to distinguish the behavior of alcoholic precursor mixtures. In the case of using pyrene as a fluorescent probe, the ratio between two peaks from the pyrene emission spectra (I/I) strongly decreased as hydrophobic micro-surroundings formed due to the self-assembly process. The UV-VIS spectra of a cationic dye solution, R6G, was studied because dilute solutions of the dye in equilibrium form measurable ratios of dimers and monomers. The absorbance was modified as micro-surroundings with different polarities were formed. These three methods demonstrated that nano-structuration was present prior to the occurrence of the sol-gel process. The combination of CTMS with other alkyltrialkoxysilane precursors having hydrocarbon chain lengths between C and C provided further evidence for a nonlinear dependence of the refractive indice and fluorescence spectra of pyrene. The properties of the final hybrids obtained by the sol-gel process were significantly affected by the precursor hydrocarbon chain lengths. DSC, XRD and FTIR measurements were used to show the plasticizing phenomena of C as other alkyltrialkoxysilanes (i.e., C-C) were added.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Recently, Ni3.5Sn4 intermetallic has been reported as an efficient buffering material for Si-containing composite negative electrodes used in Li-ion batteries. In the present work, the electrochemical properties of this Ni-overstoichiometric compound are studied in detail. Micrometric, nanosized and carbon-added nanosized Ni3.5Sn4 have been investigated. For all materials, very good cycle life is obtained over more than 400 cycles. Nanosized Ni3.5Sn4 with crystallite size of 6nm exhibits a reversible capacity of 240mAhg−1, ten times higher than for the micrometric state. Moreover, nanosized Ni3.5Sn4 exhibits high-rate capability with 80% of full discharge capacity at 16C. Carbon addition slows down kinetics but increases the reversible capacity up to 273mAhg−1. The electrochemical properties of nanostructured Ni3.5Sn4 phase make it a promising constituent for composite anodes of Li-ion batteries. [Copyright &y& Elsevier]

Abstract: Thanks to excellent mechanical and biochemical properties, the nickel–titanium shape memory alloy (Nitinol) constitutes an increasingly praised platform material in dental, cardiovascular and orthopedic biomedical devices. In order to strengthen their protective abilities toward corrosion, to reinforce their biocompatibility and to confer them specific osseointegrative capacities, Nitinol plates are covered with a thin tantalum layer by electrodeposition in the 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid. XPS and SEM/EDX analyses highlight the chemical and morphological characteristics of the deposits: notably, these present an intrinsic dimpled nanometric structuration which is particularly remarkable considering the “soft” experimental conditions and very interesting for fundamental and applied bioactive perspectives. The present study investigates the specific and synergic effects of the Ni occurrence on the surface of the Nitinol substrates, the presence of fluorine species in the working bath, and the electrodeposition duration on the resulting formation process, morphology and chemical composition of the tantalum coating. Finally, samples are submitted to electrochemical characterizations and in vitro hydroxyapatite growth tests for a primary assessment of their corrosion resistance and osseoinductive features. [Copyright &y& Elsevier]

Abstract: We report on the combination of nanosphere lithography, electrodeposition and click chemistry to produce nanostructured surfaces with improved number of anchored molecules. Our strategy was developed here for the immobilization of ferrocene at glassy carbon electrode, both used as models. The nanostructuration of the surface was obtained by adsorption of 900nm-diameter polystyrene nanosphere followed either by electropolymerization of N-(10-azidodecyl)pyrrole or by electrografting of 4-azidobenzenediazonium. In the case of poly-N-(10-azidodecyl)pyrrole, the AFM analysis of the surface after electropolymerization and removal of the nanospheres show the formation of a patterned film with holes separated of ≈900nm. In the case of 4-azidobenzenediazonium, the electrografting proceeds similarly to bare surfaces, but with a decrease of reduction peak intensity due to the partial coverage of the electrode surface with insulating nanospheres. For both modified surfaces, the immobilization of ferrocene by copper(I) catalyzed azide-alkyne cycloaddition was clearly evidenced by cyclic voltammetry. The evaluation of the surface coverage shows that the nanostructuration leads to larger specific area for the chemical anchorage of ferrocene. Finally this procedure produces versatile functionalization of conductive materials used in various applications. [Copyright &y& Elsevier]

The AlCuFe quasicrystal phase, prepared by arc-melting and nanostructured using high energy ball milling technique, was studied employing X-ray diffraction, transmission electron microscopy, ferromagnetic resonance and electric transport measurements. Fe local environments were studied by Mössbauer spectroscopy. The resistivity ratio R(4.2 K)/R(300 K) is within the expected values commonly observed in an icosahedral phase. In general, the experimental results show that an appropriate heat treatment of the as-cast alloy prepared by arc-melting makes possible to obtain good quasicrystal samples. On the other hand, for milling time longer than five hours, the average grain-size of quasicrystal phase reduces, but it preserves Fe local atomic orders. It is also observed that the quasicrystalline sample decomposes in an iron rich nano-quasicrystalline phase and a ε-AlCu phase. Electric transport measurements show that at low temperatures the nano-quasicrystalline samples behave strongly different to their solid counterparts, an effect attributed to a long-range order reduction and an increasing of grain boundary regions. The presence of local magnetic moments in the nanostructured sample is also discussed. [ABSTRACT FROM AUTHOR]

Abstract: High pressure torsion (HPT) tests can be used to transform the structure of materials. Several studies in the literature highlight that such tests are a means of investigating certain formation mechanisms of Tribological Transformed Structures (TTS) outside contacts, as they reproduce conditions that are close to those found inside them (quasi-hydrostatic pressures and shearing) under conditions that are easier to control than in a real contact. As there is no unique path leading to deformation with TTS in real contacts, it has been decided to simplify the history of deformation as the first step in investigating the occurrence of TTS. In this study, a Bridgman anvil apparatus, which allows shearing samples in torsion under pressure, is used to test ultra high purity iron (99.99999%) with an initial grain size of 100μm, under a mean pressure of 0.5GPa. The microstructural investigations led to establishing a map identifying the refined zones within the volume of the sample and linked to contact conditions. This work considers these zones with the finest microstructure (size grains of about 220nm) as “TTS”. The experimental study is coupled with finite element analysis to investigate the specificity of the stress and strain cycles of the microstructure produced. Although further work is needed to validate the suggested comparison to friction induced transformed layers, the results showed that “TTS” are produced in a specific sample volume linked to sliding/adhesion contact conditions. The coupling between experiments and modeling shows that “TTS” formation can be associated with high hydrostatic stress components, high local plastic strains and high strain gradients. [Copyright &y& Elsevier]

Abstract: Self-organized block copolymers can be effectively utilized as nanostructured precursors to functionalized ordered mesoporous polymeric materials. Novel nanoporous polystyrene frameworks with carboxylic acid (COOH)-coated pore walls were obtained from the selective degradation of the polyester block in polystyrene-block-poly(d,l-lactide) (PS-b-PLA) diblock copolymers. By resorting to an asymmetric difunctional initiator, an orthogonal atom transfer radical polymerization (ATRP)/ring-opening polymerization (ROP) tandem approach enabled the synthesis of such diblock copolymers with a carboxyl group at the junction point between both blocks. Upon the shear flow induced by a channel die processing, highly oriented copolymers were afforded as evidenced by small-angle X-ray scattering (SAXS). Under mild alkaline conditions, the quantitative hydrolysis of the PLA nanodomains yielded ordered mesoporous materials containing nanoscopic channels lined with chemically accessible and modifiable COOH functional groups. The PS-b-PLA precursors were carefully analyzed by size exclusion chromatography (SEC) and 1H NMR, while the resulting porous frameworks were investigated by scanning electron microscopy (SEM) and nitrogen sorption porosimetry. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a new method to prepare fluorinated coatings with mechanical properties enhanced has been developed. Pyridinium, imidazolium, and phosphonium ionic liquids have been synthesized and used as new synthetic building blocks in a polytetrafluoroethylene matrix. The strategy demonstrated using long alkyl chain cations provides an opportunity to prepare nanomaterials with a nanoscale structuration. The design of these new ionic and nanostructured materials is very dependent on the cation–anion combination of ILs. The morphology analyzed by transmission electronic microscopy (TEM) shows that it is clearly tuned by the chemical nature of ILs. The finest structuration leads to a dramatic compromise between stiffness and deformation of material. The small-angle X-Ray scattering (SAXS) shows the evolution of the ionic networks during the mechanical sollicitation. [Copyright &y& Elsevier]

Abstract: A modified Metropolis atomistic simulation is proposed to model the structure of grain boundaries (GBs) and interfaces in ionic nanostructured systems and is applied to the magnetically interesting case of iron trifluoride (FeF3). We chose long-range interatomic potentials adjusted on experimental results and adapted a previously established Monte Carlo scheme consisting of various modifications of the simulated annealing/Metropolis algorithm. Atomic structures of twisted and tilted GBs as a function of the relative disorientation of the grains have been achieved yielding close to experimentally measured properties. This approach takes into account the structure of the grains far from the interface in order to constrain the relative orientation of the grains, without any periodic boundary conditions. One concludes that a long-range Coulombic fall off of the interatomic potentials is necessary to obtain GB structures presenting a correct local topology but with a smooth transition from crystalline to amorphous states. The structural features are finally discussed in terms of topological aspects and local magnetic structure. [Copyright &y& Elsevier]

In this article, we show that by biopatterning probe molecules at the nanoscale using soft lithography, protein biochips can be produced at a significantly lower cost for their use as a systematic method of molecular analysis for medical diagnosis purposes. The combination of multiplexed nanoscale microcontact printing and label-free optical detection using the principle of light diffraction is implemented for generating engineered glass slides for analysis, and a dedicated diffractive scanner for reading the multiplexed results of an assay. [ABSTRACT FROM AUTHOR]

This paper is a review that is focused on ionomers based on aromatic polysulfone backbone and intended to be used in proton exchange membrane fuel cells or in direct methanol fuel cells. Emphasis is placed on the different chemical routes to prepare the ionomers. Special attention is given to the impact of the ionomer structure on the conductivity performance and on the dimensional stability of the membranes at high temperatures. [ABSTRACT FROM AUTHOR]

Although boiling process has been a major subject of research for several decades, its physics still remain unclear and require further investigation. This study aims at highlighting the effects of surface wettability on pool boiling heat transfer. Nanocoating techniques were used to vary the water contact angle from 20 to 1100 by modifying nanoscale surface topography and chemistry. The experimental results obtained disagree with the predictions of the classical models. A new approach of nucleation mechanism is established to clarify the nexus between the surface wettability and the nucleate boiling heat transfer. In this approach, we introduce the concept of macro- and micro- contact angles to explain the observed phenomenon. [ABSTRACT FROM AUTHOR]

Abstract: Poly[Styrene-b-Butadiene-b-(Methyl Methacrylate)], SBM triblock copolymers have been incorporated in different polyurethane, PU formulations in order to prepare nanostructured materials. Macrodiols used for PU synthesis were based on a central bis-phenol A, BPA unit with two hydroxyl-terminated oligo(oxypropylene), BPA-POx or oligo(oxyethylene), BPA-EO chains with varying lengths. The initial solubility of the three blocks and the rheological behavior of the solutions in macrodiols and also in two diisocyanates, isophorone diisocyanate, IPDI, and 1,3-xylylene diisocyanate, XDI have been first characterized. The PMMA block is the most soluble and its role during the reaction is to stabilize the initial nanostructure or to control the reaction-induced microphase separation. Block copolymers can be dissolved first in the macrodiol, or preferably in the diisocyanate. With BPA-POx and low SBM content (<10wt%), transparent linear or crosslinked PU with well dispersed triblock nanoparticles have been prepared, depending on the molar mass of the macrodiol and on the concentration of diblock SB impurities present in the triblock. For high SBM concentrations (>50wt%), a twin screw extruder had to be used for the blending. Under well-defined conditions, transparent linear PUs and linear segmented polyurethane-ureas have been prepared. This study confirms that for designing a nanostructured material from a reactive mixture with a triblock additive, one block, called “the nanostructuring block” has to remain soluble up to the end of the reaction. [Copyright &y& Elsevier]

In the Li-ion technology, the diffusion of Li in the electrode is often limited by the quality of interfaces. Two synthetic approaches are proposed to develop the transition metal phosphides (TMP)/electrolyte interface. The first route consists in the preparation of nickel nanopowder by solution phase synthesis, and the second is based on the electrochemical synthesis of nickel nanorods in a template followed by vaporization of phosphorous. In the former, the nanosized metallic particles are foreseen to be used as starting nanomaterial to directly react with phosphorous agents (P or Li3P) during the cycling of the lithium battery. A preliminary electrochemical test of the NiP x nanorods/Li half-cell shows the feasibility of the use of such nanostructured TMP electrode in a Li battery. [ABSTRACT FROM AUTHOR]