Microscopic dynamics of confined supercritical water

We present the first study of the microscopic dynamics of confined supercritical water. Our results have been obtained by molecular dynamics simulations of supercritical water adsorbed inside carbon nanotubes. Water-water interactions were accounted by means of a flexible simple point charged potential whereas water-carbon interactions were modeled by Lennard-Jones forces. Diffusion coefficients and relaxation times of water molecules have been analyzed. Absorption lineshapes indicate that microscopic dynamics is dominated by a competition between confinement and thermal effects. (C) 2002 Published by Elsevier Science B.V.