Analysis of membrane formation via nonsolvent induced phase separation by dissipative particle dynam

• 作 者: Han-han Lin Yuan-hui Tang Xiao-lin Wang
• 机 构: Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Ts
• 出 处: 第九届全国膜与膜过程学术报告会
• 发表日期: 2016年8期
• 关键词: Nonsolvent induced phase separation membrane Dissipative particle dynamics Mass

　　The membrane formation process via nonsolvent induced phase separation (NIPS) was investigated by dissipative particle dynamics simulations on the mesoscopic scale.The effect of the interphase mass transfer on the membrane formation process and the membrane morphology was elaborately analyzed.Factors including the interaction between the solvent and the nonsolvent,the polymer concentration and the nonsolvent bath temperature were considered.The results showed that as the interaction between the solvent and the nonsolvent got better,the mass transfer was intensified which contributed to a intenser phase separation and thereby the asymmetric membrane structure with a thick dense surface layer and a porous sub-layer would be formed.With the nonsolvent temperature raising,the relatively symmetric structure with the small pores was obtained due to the declined polymer aggregation rate and the increased phase separation rate caused by the accelerated mass transfer.As the polymer concentration increased,the flexibility of the system reduced and thereby the phase separation slowed down,resulting in highly asymmetric membrane structure with a thicker and denser surface layer and a more porous sub-layer formed.The analysis of the effects on the mass transfer in this study benefits to a better control of membrane preparation via NIPS.