The molecular dynamics simulation of hydrogen bonding in supercritical water

Molecular dynamics simulation was used to research the hydrogen bonding kinetics of methane and urea in supercritical water. Above the critical point, the tetrahedral structure typical of liquid water at room temperature is substituted by chains of hydrogen-bonded molecules in supercritical water model. Moreover, urea does not cause long-term interference with the order of water, and methane can be dissolved in supercritical water due to the destruction of the hydrated shell. According to the study of diffusion, the viscosity of water decreases with increasing temperature and increases with increasing concentration. The reason for the difference in the diffusion rate between the two solutes is related to their relative molecular mass and hydrogen bonding. (C) 2018 Elsevier B.V. All rights reserved.