Switchable hydrophobic-hydropholic fluorinated layer for offset processing

The use of heat-sensitive printing plate precursors has become very popular as one of the‘dry’ lithographic methods that have recently been proposed to comply with environmentalrequirements, A major problem associated with most ablative plates, however, is thegeneration of ablation particles that may contaminate the electronics and optics of thedevice. The objective of the present study is to provide a ‘processless’ method, through aplasma-enhanced fluorination (PEF) treatment involving a fluorinated gas [1]

From irreversible transformation of VO2 to V2O5 electrochromic films

Since its discovery, electrochromism, known as a modulation of the optical properties under an applied voltage, has attracted strong interest from the scientific community and has proved to be of significant utility in various applications. Although vanadium dioxide (VO2) has been a candidate of extensive research for its thermochromic properties, its intrinsic electrochromism has scarcely been reported so far. In this study, multi-electrochromism is described from VO2 thick films. Indeed, VO2 opaque film, doctor bladed from homemade monoclinic VO2 powder, shows a pronounced color modulation from orange to green and blue associated with an amorphization-recrystallization phenomenon upon cycling in lithium-based electrolyte. The strong memory effect allows to follow the coloration mechanism by combining various ex-situ and in-situ characterizations addressing both structural and electronic aspects. Upon cycling the multi-chromism of VO2 finds its origin in a transformation of VO2 into orange-V2O5 on oxidation while in reduction the blue color lithiated state illustrates a mixed vanadium oxidation state

Investigation of the interaction between adsorbed water and various morphologies of boehmite nanoparticles prepared by continuous supercritical hydrothermal synthesis

Boehmite applications are often subject to specific characteristics in terms of morphologies and surface properties. The versatile continuous supercritical hydrothermal method allows synthesizing various boehmite morphologies from rhombic to hexagonal platelet-like nanoparticles depending on the preferential adsorption of part of the precursor after transformation species on the (020) surface resulting in a preferential growth along [001] and mostly [100] directions. This adsorption on surface free sites plays the role of morphology stabilizer and results in the reduction of adsorbed water. The interaction between adsorbed water and the boehmite morphology depends on various parameters: 1) the structure order of boehmite as exhibited by XPS analysis associated with 1H Solid-State NMR spectroscopy and, 2) the number of available free sites, which tend to be filled by the adsorption of nitrates as observed by Raman spectroscopy

Fluoration douce et topotactique de composés intermétalliques/ Le rôle clef de la liaison C−F

International audienc

Improved electrochemical performance for high voltage spinel LiNi0.5Mn1.5O4 modified by supercritical fluid chemical deposition

International audienceAmong candidates at the positive electrode of the next generation of Li-ion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi0.5Mn1.5O4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al2O3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes

Improved electrochemical performance for high voltage spinel LiNi0.5Mn1.5O4 modified by supercritical fluid chemical deposition

International audienceAmong candidates at the positive electrode of the next generation of Li-ion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi0.5Mn1.5O4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al2O3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes

Radiolabeling, Quality Control and In Vivo Imaging of Multimodal Targeted Nanomedicines

International audienceFollowing our previous study on the development of EGFR-targeted nanomedicine (NM-scFv) for the active delivery of siRNA in EGFR-positive cancers, this study focuses on the development and the quality control of a radiolabeling method to track it in in vivo conditions with nuclear imaging. Our NM-scFv is based on the electrostatic complexation of targeted nanovector (NV-scFv), siRNA and two cationic polymers. NV-scFv comprises an inorganic core, a fluorescent dye, a polymer layer and anti-EGFR ligands. To track NM-scFv in vivo with nuclear imaging, the DTPA chemistry was used to radiolabel NM-scFv with 111In. DTPA was thiolated and introduced onto NV-scFv via the maleimide chemistry. To obtain suitable radiolabeling efficiency, different DTPA/NV-scFv ratios were tested, including 0.03, 0.3 and 0.6. At the optimized ratio (where the DTPA/NV-scFv ratio was 0.3), a high radiolabeling yield was achieved (98%) and neither DTPA-derivatization nor indium-radiolabeling showed any impact on NM-scFv’s physicochemical characteristics (DH ~100 nm, PDi < 0.24). The selected NM-scFv-DTPA demonstrated good siRNA protection capacity and comparable in vitro transfection efficiency into EGFR-overexpressing cells in comparison to that of non-derivatized NM-scFv (around 67%). Eventually, it was able to track both qualitatively and quantitatively NM-scFv in in vivo environments with nuclear imaging. Both the radiolabeling and the NM-scFv showed a high in vivo stability level. Altogether, a radiolabeling method using DTPA chemistry was developed with success in this study to track our NM-scFv in in vivo conditions without any impact on its active targeting and physicochemical properties, highlighting the potential of our NM-scFv for future theranostic applications in EGFR-overexpressing cancers

Multi-scale characterization of submicronic NASICON-type solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 degraded by spark plasma sintering

One of the most promising and developed disruptive technology of energy storage for the future is all solid-state batteries. The NASICON phase LATP (Li1.3Al0.3Ti1.7(PO4)3) is widely studied especially thanks to its high ionic conductivity and mechanical strength. However, high temperature densification is required to obtain a dense and conductive material. Here we explore the fast sintering by Spark Plasma Sintering (SPS) of submicronic LATP particles, and the impact of the heating rate on the physico-chemical and transport properties of the pristine powder. High-speed rate for the sintering process induces particles’ growth, avoiding any reduction of titanium. The impurity AlPO4 plays a major role on the conductivity, depending on its content but also on its distribution within the composite, either as a coating (surface modification) or as crystalline particles within the grain boundaries. An intimate understanding of the ceramic composites was achieved using combination of advanced characterization techniques to get a multi-scale description of the material, from the pristine to the sintered states, from the surface to the bulk, and from the atomic long range to the local scales. Sharing these fundamental results is essential, with among other motivations, the spreading of our interpretation of complex spectroscopic results (Electronic Spin Resonance (ESR) spectroscopy, solid-state Nuclear Magnetic Resonance (NMR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS)), key for characterization of reactivities at interfaces in this work and in others.Laboratory of excellency for electrochemical energy storag

Nitrogen radiofrequency plasma treatment of graphene

The incorporation of nitrogen (N) atoms into a graphitic network such as graphene (Gr) remains a major challenge. However, even if the insertion mechanisms are not yet fully understood, it is certain that the modification of the electrical properties of Gr is possible according to the configuration adopted. Several simulations work, notably using DFT, have shown that the incorporation of N in Gr can induce an increase in the electrical conductivity and N acts as an electron donor; this increase is linked to the amount of N, the sp 2 /sp 3 carbon configuration, and the nature of CÀ N bonding. Nitrogen radio-frequency (RF) plasma has been used to incorporate N into Gr materials. The RF plasma method shows the possibility to incorporate N-graphitic nitrogen into Gr after a pre-treatment with nitric acid. X-ray photoelectron spectroscopy and Raman spectrometry were used to quantify the functionalized groups. The modifications of the graphene surface chemistry along the amount of N inside the Gr change the chemical environment of N. This method, enabling the incorporation of N inside Gr matrix, opens up a route to a broad range of applications

Designing CuO–SiO2 and Cu0–SiO2 Monolithic Ceramics Bearing Hierarchical Porosity Toward Robust and Cycling CO Oxidation Properties

International audienceIn the general context of environmental air remediation, copper-oxide-based self-standing porous catalysts (MUB-103(x)) and their reduced homologues (Red MUB-103(x)) have been synthesized and studied for the thermoconversion of CO to CO2. Catalytic experiments under dry air conditions reveal that for nonreduced catalysts, increasing the Cu content diminishes the light-off temperature T50 (corresponding to 50% conversion). The catalytic performances exhibited by the CuO phase dispersed in the silica pores of MUB-103(x) samples are the highest reached to date despite the limitations of the experimental conditions used. After reduction with H2, the native Red MUB-103(x) catalysts offer CO conversion efficiencies significantly more increased, leading to a lowering of the T50 values equal to at least 100°C. As such, the CO conversion reaches a T50 value of 160 °C for Red MUB-103(2) with 1.81 wt % Cu; this catalyst displays a specific rate of 8.6 mmolCO gCu–1 s–1 at 175 °C, largely higher than those observed to date. The performances of the Red MUB-103(2) sample were evaluated for CO oxidation under humid conditions with the addition of 5 vol % water vapor in the feed during four cycles, leading to the same efficiency when compared with that under dry experimental conditions, revealing robustness. A drastic increase in the CO conversion temperature was observed for the 4th cycle, i.e., after 8 h under humid conditions. Analyses of the spent Red MUB-103(2) catalyst after four cycles reveal a slight oxidation of copper, leading to Cu2O species. Importantly, after four cycles, the deactivated catalyst was able to partially recover its performance when reactivated through a 2 h reducing treatment under H2 at 400 °C