Asymmetric self-diffusion with orientation-dependence of water molecule in finite timescale  

作　　者：Xu Wei Nan Sheng RongZheng Wan GuoHui Hu HaiPing Fang 

机构地区：[1]Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University [2]Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology,Shanghai Institute of Applied Physics,Chinese Academy of Sciences

出　　处：《Science China(Physics,Mechanics & Astronomy)》2016年第7期20-24,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11175230 and 11474299);the Innovation Program of Shanghai Municipality Education Commission,China(Grant No.14ZZ095)

摘　　要：Self-diffusion of water has been investigated by molecular dynamics simulations. It was found that the preference of the direction in self-diffusion of water is orientation dependent in a finite time. For a time of-lO0 ps, there are more possibilities for water molecules moving along the initial dipole orientation than in the opposite direction. This reveals that self-diffusion of water molecules is asymmetric in a finite time. We tested four water models and found that they all show similar asymmetric diffusion, indicating that asymmetric diffusion of water is intrinsic behavior rather than induced by the water model. These results are important for understanding and application of asymmetric diffusion in research fields such as biological water and confined water in small dimensions.Self-diffusion of water has been investigated by molecular dynamics simulations.It was found that the preference of the direction in self-diffusion of water is orientation dependent in a finite time.For a time of^100 ps,there are more possibilities for water molecules moving along the initial dipole orientation than in the opposite direction.This reveals that self-diffusion of water molecules is asymmetric in a finite time.We tested four water models and found that they all show similar asymmetric diffusion,indicating that asymmetric diffusion of water is intrinsic behavior rather than induced by the water model.These results are important for understanding and application of asymmetric diffusion in research fields such as biological water and confined water in small dimensions.

关 键 词：water DIFFUSION dipole orientation asymmetry 

分 类 号：O552.2[理学—热学与物质分子运动论]