Calculation on phase diagrams of polyetherimide/ N,N-dimethylacetamide/H2O-BuOH casting system and their relevance to membrane performances  

作　　者：Ming TAN Gaohong HE Yan DAI Rujie WANG Wenhua SHI 

机构地区：[1]State Key Laboratory of Fine Chemicals, R&D Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China [2]Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China

出　　处：《Frontiers of Chemical Science and Engineering》2014年第3期312-319,共8页化学科学与工程前沿（英文版）

摘　　要：The ternary phase diagrams of polyetherimide （PEI）/N,N-dimethylacetamide （DMAc） with H2O and BuOH as non-solvent were simulated using solubility parameter and Flory-Huggins theory. The phase diagrams show that 5.5% H2O/BuOH system containing 5% BuOH and 0.5% H2O or 6.5% H2O/BuOH system containing 6.2% BuOH and 0.3% H2O is required to induce liquid- liquid demixing for 20 wt-% PEI/DMAc casting solution. Therefore, BuOH can enhance the phase separation of the PEI casting solution and hereby induce higher porosity of the membrane, and the diffusion of BuOH into the water coagulation bath causes larger pore size easily compared with DMAc. Our predictions that the membrane pure water flux first increases then decreases, and the rejection ratio of bovine serum albumin decreases with the increasing concentration of BuOH were validated by the experiments using the prepared membranes.The ternary phase diagrams of polyetherimide （PEI）/N,N-dimethylacetamide （DMAc） with H2O and BuOH as non-solvent were simulated using solubility parameter and Flory-Huggins theory. The phase diagrams show that 5.5% H2O/BuOH system containing 5% BuOH and 0.5% H2O or 6.5% H2O/BuOH system containing 6.2% BuOH and 0.3% H2O is required to induce liquid- liquid demixing for 20 wt-% PEI/DMAc casting solution. Therefore, BuOH can enhance the phase separation of the PEI casting solution and hereby induce higher porosity of the membrane, and the diffusion of BuOH into the water coagulation bath causes larger pore size easily compared with DMAc. Our predictions that the membrane pure water flux first increases then decreases, and the rejection ratio of bovine serum albumin decreases with the increasing concentration of BuOH were validated by the experiments using the prepared membranes.

关 键 词：phase diagram solubility parameter interaction parameter ULTRAFILTRATION Flory-Huggins theory 

分 类 号：TQ225.261[化学工程—有机化工] TQ323.7