Structure properties of mixtures composed of ethanol and water by molecular dynamics simulation

Transport properties of various mixtures of ethanol and water at different concentrations evaluated at temperatures 298.15K and pressure 1bar by MD method (molecular dynamics) simulation. Obtained results from study showed that the self-diffusion coefficients of ethanol and water in mixtures are in nearly qualitative agreement with the experimental data. The self-diffusion coefficients are increasing when the concentration of the water is increased. We have also observed that the first peak of the radial distribution functions ascended when the water concentrations decreased. The results indicated that the oxygen in ethanol (Oe) has a maximum interaction with ethanol hydrogen (He) at low mole fraction of ethanol. Therefore, it can be concluded that probability of existence of Oe around the He of ethanol molecule is higher than the water atoms at low mole fraction of ethanol. The higher the first peak heights is, the stronger the interactions of two water molecules can be. Therefore, the self-diffusion coefficients will decrease while the water concentrations are decreasing. Coordination numbers of water–water structure are more than the ethanol–ethanol structure coordination numbers. With the enhancement of coordination numbers, more molecules participated in the reaction, hence stronger bounds formed between molecules.