高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

水和盐分子在反渗透膜内扩散过程的分子模拟

刘清芝1, 杨登峰1, 胡仰栋2   

    1. 青岛农业大学化学与药学院, 青岛 266109;
    2. 中国海洋大学化学化工学院, 青岛 266100
  • 收稿日期:2008-05-04 修回日期:1900-01-01 出版日期:2009-03-10 发布日期:2009-03-10

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

LIU Qing-Zhi1*, YANG Deng-Feng1, HU Yang-Dong2   

    1. Chemistry and Pharmacy Science College, Qingdao Agricultural University, Qingdao 266109, China;
    2. College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
  • Received:2008-05-04 Revised:1900-01-01 Online:2009-03-10 Published:2009-03-10

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被引次数

32

摘要： 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.

关键词: 分子模拟, 反渗透膜, 扩散系数, 膜材料

Abstract: 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 membranes we simulated, the diffusion coefficient value of Na+ and Cl- had much difference. The movement of NaCl molecule was restricted by the ions which moves slowly. Diffusion process of salt molecule in the membrane was only restricted by the membrane species, without relationship with salt molecules itself. Movement of molecule of water was not affected by the kinds of salt molecules in the same membrane.

Key words: Molecular simulation, Reverse osmosis membrane, Diffusion coefficient, Membrane material

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