OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 16766To link to this article :

Environmentally compliant organic–inorganic hybrid coatings for efficient corrosion protection of metallic surfaces are potential alternatives to the current method based on chromate passivation.

International audienceNaSICON-type lithium conductor Li1.3Al0.3Ti1.7(PO4)3 (LATP) is synthesized with controlled grain size and composition using solution chemistry. After thermal treatment at 850 °C, sub-micronic crystallized powders with high purity are obtained. They are converted into ceramic through Spark Plasma Sintering at 850-1000 °C. By varying the processing parameters, pellet with conductivities up to 1.6 × 10−4 S/cm with density of 97% of the theoretical density have been obtained. XRD, FEG-SEM, ac-impedance and Vickers indentation were used to characterize the products. The influence of sintering parameters on pellet composition, microstructure and conductivity is discussed in addition to the analysis of the mechanical behavior of the grains interfaces

International audienceCarbon nanotubes with 2, 3, 8 and 20 walls are mixed with a copper powder (micrometer sized) and consolidated by spark plasma sintering. The microhardness of resulting composites is found to be over 50% higher than that for Cu and the friction coefficient against a steel ball is decreased by a factor of 3-4 while the wear and wear rate are reduced by a factor of 10-20. Raman maps of selected specimens outside and inside the worn surface show that double-wall carbon nanotubes remain intact. The reasons for the effect of the number of walls and carbon content are discussed

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Ionogel A B S T R A C TAn inorganic gel polymer electrolyte based on the confinement of an ionic liquid mixture (1:1 by weight or molar ratio) of N-methyl-N-propylpiperidinium bis(fluorosulfonyl)imide (PIP13FSI) and N-butyl-Nmethylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) into a SiO 2 matrix prepared from a sol-gel method was prepared and further used as electrolyte in an all solid-state supercapacitor. The synthetized ionogel exhibits a high ionic conductivity over a wide temperature range (from 0.2 mS cm À1 at À40 C up to 10 mS cm À1 at 60 C). The ionogel-based supercapacitor using two activated carbon electrodes can be operated over 3 V cell voltage window. Moreover this all solid-supercapacitor shows a capacitance up to 90 F g À1 at room temperature. These encouraging results show the interest of developing such devices, including non-toxic and safer electrolytes, packaging issues and flexible devices development.

Effect of cerium on structure modifications of a hybrid sol-gel coating, its mechanical properties and anti-corrosion behavior. Materials Research Bulletin, Elsevier, 2012, vol. 47, pp. 3170-3176 OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible.

No abstract

Stainless steels are increasingly used in the aeronautics field for the manufacture of structural parts. One of them, the X13VD martensitic stainless steel (X12CrNiMoV12-3), known for its good mechanical properties, has a poor corrosion resistance in confined or severe environments. In the past years, Cr(VI) based pre-treatments have been currently used for corrosion protection of different metals, however, they are toxic and due to environmental regulations, they will be definitely banned in a near future. Alternatives to replace Cr(VI) show advantages and drawbacks considering key properties such as: corrosion resistance, adhesion of coatings, fatigue resistance, durability and reliability. However, some of their possible alternatives show high potential. In this paper, a process was developed to improve the corrosion resistance of the martensitic stainless steel. Organic-inorganic hybrid coatings with different cerium concentrations were deposited onto stainless steel by sol-gel process. Corrosion resistance of the coatings was evaluated by electrochemical impedance measurements and it has been proved that cerium concentration of 0.01 M into hybrid coating was an optimal content. Adhesion tests were also carried out by "nanoscratchtest" to characterize the coatings mechanical properties as a function of cerium concentration but results do not clearly show the influence of cerium for the coating adhesion toward the substrate. To try to correlate with the electrochemical properties, liquid 29 Si NMR spectroscopy was then performed to investigate hydrolysis and condensation reactions of sol-gel process, and by this method, it was demonstrated that for higher cerium concentration (>0.01 M) there is a modification of the chemical structure of the sol-gel network.