Search results for "Material chemistry"

Large scale vertically aligned carbon nanotubes: synthesis by CCVD and multifunctional materials

2014

International audience

Propriétés mécaniques, thermiques et électrioques de composites à matrice SiC nanostructurée renforcée par des nanotubes de carbone

2014

International audience

Composites nano-SiC/Nanotubes de carbone frittés par SPS: Elaboration et influence de la teneur en NTC sur les propriétés mécaniques

2014

International audience

Elaboration of nano-SiC/Carbon nanotubes composites: mechanical, thermal and electric properties

2015

International audience

The detection of material reuse in ancient construction. What is the role of dating methods?

2019

Modélisation de phénomènes locaux : vers leur prise en compte dans la simulation de la cinétique d'oxydation d'un métal.

2006

The oxidation of metals is a complex process involving several mechanisms that take place at different length scale (macroscopic and microscopic). In this work, we try to integrate local phenomena (microscopic scale) in macroscopic models, especially to the modelling of the metal oxidation kinetics. The study is divided in two parts ; the first one based on non-equilibrium thermodynamics allows us to obtain the evolution laws of the system metal/oxyde, those were used to modelling oxidation kinetics. The second one is microscopic ; it consists in a study of the thermo-mechanical behaviour of various aluminium surfaces by molecular dynamic and the calculation of their surface energy density.…

Interfaces électrochimiques et couches minces sondées par ellipsométrie

2020

Spectroscopic ellipsometry (SE) is a non-invasive, non-destructive, and contactless optical technique which is based on the change in the polarization state of light as it is typically reflected from a thin film sample. Often seen primarily as ex situ or of particularly helpful interest to control in situ vacuum growth processes, SE can also be promoted as an analytical tool to diagnose electrolyte-electrode interface during wet processes. I will mainly highlight in this document my researches contributions in this field: (i) the very early growth stages of bismuth telluride electrodeposition, (ii) the physico-chemical properties of oxides grown in the early regime of plasma electrolytic ox…

Initial stages of metal oxides thin films growth by MOCVD: physicochemical characterisation of the film/substrate interface

2006

The initial stages of Metalorganic Chemical Vapour Deposition (MOCVD) of TiO2 thin films on Si(100) were studied in situ by surface analyses (XPS, ARXPS, AES). An original experimental set-up was built for this purpose and developed. Information obtained from these in situ experiments was completed by ex situ characterisations (HRTEM, SIMS, GIXRD...).The formation of an interfacial SiOy<2 layer resulting of the interaction of the precursor Ti(OCH(CH3)2)4 with the substrate takes place before the formation of stoichiometric TiO2 and leads to the presence of carbon at the interface. At the deposition temperature, 675 °C, silicon diffusion within the TiO2 external layer was also revealed. Conc…

Study of the action of phosphate ions contained in the mixing water of the hydration of a Portland cement.

2005

Cementation is considered as the most attractive solution for the conditioning of low and intermediate radioactive wastes. The species contained in these wastes can strongly influence the reactivity of the cement pastes, it is in particular the case of the ortho-phosphate ions which are found in the evaporation concentrates. The aim of our work was to determine the influence of these ions on the hydration and the rheological properties of the cement pastes at early age as well as the mechanical and physical properties on the hardened material.

Elaboration and interfacial reactivity of Lanthanum Strontium Chromium Ruthenium (LSCrRu) perovskite oxides as intermediate temperature fuel cell (IT…

2005

New data on the interest of ruthenium doped lanthanum strontium chromite La1-xSrxCr1-yRuyO3δ (LSCrRu) as anode in ITSOFC are presented. Microwave synthesis of mixed oxides allowed shaping of half-cells and complete cells using sputtering and screen printing methods. LSCrRu methane reforming property had been studied in a mono-chamber system coupled with a mass spectrometer in collaboration with Institut de REcherche Hydro-Québec. Anode/electrolyte interfacial reactivity had been analysed using SIMS and XRD on half cells models after ageing under H2 at 800°C. This experiment gave the chemical composition of the film after treatment. Complete cells, tested under working conditions, highlight…