Probing individual saturations of crude-oil/brine/mud-filtrate mixtures confined in rocks

We propose a method that allows probing quantitatively the individual saturations of crudeoil/brine/mud-filtrate mixtures during imbibition-drainage experiments on a petroleum rock-system. The experiments have been also performed at different temperature and pressure conditions

NMR investigations of water retention mechanism by cellulose ethers in cement-based materials

International audienceWe show how nuclear magnetic spin-lattice relaxation dispersion of proton-water (NMRD) can be used to elucidate the effect of cellulose ethers on water retention and hydration delay of freshly-mixed white cement pastes. NMRD is useful to determine the surface diffusion coefficient of water, the specific surface area and the hydration kinetics of the cement-based material. In spite of modifications of the solution's viscosity, we show that the cellulosic derivatives do not modify the surface diffusion coefficient of water. Thus, the mobility of water present inside the medium is not affected by the presence of polymer. However, these admixtures modify significantly the surface fraction of mobile water molecules transiently present at solid surfaces. This quantity measured, for the first time, for all admixed cement pastes is thus relevant to explain the water retention mechanism

Molecular dynamics of ionic liquids confined in solid silica matrix for lithium batteries

We present the first results of the magnetic field dependence of the longitudinal nuclear magnetic relaxation of anion-cation pair of ionic liquids (Li+-ionogels) confined within a silica-like mesoporous matrices designed for lithium batteries. These results are in favour of a very-correlated dynamical motion of the anion-cation pair within the solid and disordered silica matrix

Nuclear magnetic relaxation dispersion investigations of water retention mechanism by cellulose ethers in mortars

International audienceWe show how nuclear magnetic spin-lattice relaxation dispersion of proton-water (NMRD) can be used to elucidate the effect of cellulose ethers on water retention and hydration delay of freshly-mixed white cement pastes. NMRD is useful to determine the surface diffusion coefficient of water, the specific area and the hydration kinetics of the cement-based material. In spite of modifications of the solution's viscosity, we show that the cellulosic derivatives do not modify the surface diffusion coefficient of water. Thus, the mobility of water present inside the medium is not affected by the presence of polymer. However, these admixtures modify significantly the surface fraction of mobile water molecules transiently present at solid surfaces. This quantity measured, for the first time, for all admixed cement pastes is thus relevant to explain the water retention mechanism