Enhancement of water self-diffusion at super-hydrophilic surface with ordered water**Project supported by the National Natural Science Foundation of China (Grant Nos. 11290164, 11674345, and U1532260), the Key Research Program of Chinese Academy of Sciences (Grant Nos. KJZD-EW-M03 and QYZDJ-SSW-SLH019), the Youth Innovation Promotion Association, Chinese Academy of Sciences, the Shanghai Supercomputer Center of China, the Computer Network Information Center of

Abstract

It has been well acknowledged that molecular water structures at the interface play an important role in the surface properties, such as wetting behavior or surface frictions. Using molecular dynamics simulation, we show that the water self-diffusion on the top of the first ordered water layer can be enhanced near a super-hydrophilic solid surface. This is attributed to the fewer number of hydrogen bonds between the first ordered water layer and water molecules above this layer, where the ordered water structures induce much slower relaxation behavior of water dipole and longer lifetime of hydrogen bonds formed within the first layer.