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An efficient, environmentally friendly flame-retardant process for lignocellulosic material was developed based on a renewable phosphorus flame retardant. The whole process which is easy to implement and to scale up is patented. The effectiveness of the treatment was proved by the analyses of pyrolysis-combustion flow calorimetry (PCFC), a flame test, X-ray fluorescence, 31P and 13C NMR and optical microscopy. Grafting of ≈ 0.5%P and ≈ 0.7% N was sufficient to produce a non-flammable material by a synergistic P/N effect. This process was successfully applied to cellulosic fibers and wood particles for the production of fire-resistant wood panels. The analysis of these panels showed not only an efficiency in fire behavior but also an improvement in mechanical and hygroscopic properties. The implementation of the process in different industrial production lines will be exposed.

International audience

In this study Silver (Ag) and Gold (Au) nanoparticles (NPs) of different surface charges (positively charged, negatively charged, or nearly neutral) and sizes were obtained using ascorbic acid as a reducing agent and multiple polymers such as Chitosan (Chit), Poly-L-Lysine (PLL), Polyvinyl alcohol (PVA), Polyethylene glycol (PEG) or sodium citrate as stabilizing ligands. The obtained NPs were characterized using UV-visible spectroscopy (UV-vis), Dynamic Light Scattering (DLS), and Zeta Potential (Q measurements. On the other hand, AuNPs with different coating (PLL, PVA and PEG) and charges were tested on whole human blood samples, specifically on neutrophils using a Neutrophil Function Test (NFT). Our results demonstrated that AuNPs-PVA with a slight negative charge (C = -15 mV) and PEgylated AuNPs-PLL (AuNPs-PLL-PEG) with a slight positive charge (ζ = + 9 mV) were found to be the least detected by neutrophils making them suitable for biomedical applications.

International audience

International audience; Investigations within the local spin density functional theory (LSDF) of the intermetallic hydride system $ {\rm CeRhSnH_x} $ were carried out for discrete model compositions in the range $ 0.33 \leq x_H \leq 1.33 $. The aim of this study is to assess the change of the cerium valence state in the neighborhood of the experimental hydride composition, $ {\rm CeRhSnH_{0.8}} $. In agreement with experiment, the analyses of the electronic and magnetic structures and of the chemical bonding properties point to trivalent cerium for $ 1 \leq x_H \leq 1.33 $. In contrast, for lower hydrogen amounts the hydride system stays in an intermediate-valent state for cerium, like in $ {\rm CeRhSn} $. The influence of the insertion of hydrogen is addressed from both the volume expansion and chemical bonding effects. The latter are found to have the main influence on the change of Ce valence character. Spin polarized calculations point to a finite magnetic moment carried by the Ce $ 4f $ states; its magnitude increases with $ x_H $ in the range $ 1 \leq x_H \leq 1.33 $.

International audience; The electronic and magnetic properties of the cubic Laves phases ZrFe2 and of its hydride ZrFe2H3,5 are studied within the density functional theory (DFT) in its local spin density approximation (LSDA) for the purpose of assessing the interplay between chemical pressures versus chemical bonding effects due to the insertion of hydrogen...

International audience; GdNi2 and GdCu2 were submitted to a high-energy ball-milling using a planetary ball-miller...