Molecular dynamics simulation of the interaction of ethanol-water mixture with a Pt surface

Abstract

An analysis of the molecular dynamics of ethanol solvated by water molecules in the absence and presence of a Pt surface has been performed using DL_POLY_2.19 code. The structure and diffusion properties of an ethanol–water system have been studied at various temperatures from 250 to 600 K. We have measured the self-diffusion coefficients of the 50:50% ethanol–water solution; in the absence of a Pt surface our results show an excellent agreement–within an error of 7.4% – with the experimental data. An increase in the self-diffusion coefficients with the inclusion of a Pt surface has been observed. The estimation of the diffusion coefficients of both water and ethanol in the presence of a Pt surface shows that they obey the Arrhenius equation; the calculated activation energies of diffusion of ethanol and water are 2.47 and 2.98 Kcal/mole, respectively. The radial distribution function graphs and density profiles have been built; their correlations with the self-diffusion coefficients of both ethanol and water molecules are also illustrated.