水和盐分子在反渗透膜内扩散过程的分子模拟

采用分子动力学模拟方法研究了水和盐分子(NaCl, MgCl2, CaSO4, K2SO4)在8种反渗透复合膜中的扩散状态及扩散系数. 并对膜材料的结构单体与水和盐分子在膜内扩散系数相关性进行了分析与讨论. 在所模拟的8种膜内, 随着膜种类的不同, 水分子在其中的扩散系数有明显的变化, 且扩散系数的变化规律与实验所得到的膜的水通量一一对应. NaCl分子中的Na+和Cl-在膜内的扩散速率不一致, 其扩散系数值在同种膜中相差较大, 且当盐分子单独存在时, 制约其在膜内扩散过程的离子只与膜种类有关, 与盐分子本身无关. 在同种膜中, 水分子的扩散过程不受体系中盐分子类型的影响.

Water and Salts Molecular Simulation of Diffusion Process in Reverse Osmosis Membrane

In this paper,we used molecular dynamic simulation method to study the diffusion process and diffusion coefficient of small molecules in reverse osmosis membrane,and made an analysis and discussion of relationship between the membranous structure monomer and the diffusion coefficients of small molecules in membrane.Among the eight kinds of membranes,diffusion coefficent of water changed obviously in different membranes and the changing direction was in accordance with experimental values.In eight kinds of m...