中文摘要：

以甲苯为溶剂,利用超临界CO2诱导相转化法制备了多孔非对称聚苯乙烯膜.通过扫描电镜对膜结构进行了表征,探讨了不同温度、压力和铸膜液中聚苯乙烯浓度对膜形态、孔径分布及膜孔隙率的影响;同时,基于Tompa扩展的Flory-Huggins聚合物溶液理论计算了聚苯乙烯/超临界CO2/甲苯铸膜体系的三元相图.研究表明,在温度为35~65℃、压力为8~16 MPa及聚合物质量分数为15%~35%条件下,制备的聚苯乙烯膜截面呈胞腔状孔结构,孔隙率为53.54%~84.67%,且孔隙率随温度、压力和聚苯乙烯浓度均呈现出先增大后减小的趋势.相图计算结果表明,温度对体系双节线位置的改变影响较小,而压力对其影响相对较大.

英文摘要：

Microporous asymmetric polystyrene（ PSt） membranes were prepared by supercritical CO2-induced phase inversion. The experiments were designed and conducted to investigate the effects of different process parameters,such as temperature,CO2 pressure and PSt concentration in casting solution,on the membrane morphologies,pore size distribution and especially on the porosity of the membranes. The ternary phase diagrams of polystyrene/supercritical CO2/toluene system were determined based on the extended FloryHuggins theory of polymer solutions of Tompa. The prepared PSt membrane had a cellular structure. The porosity of the products was in the range of 53. 54% —84. 67%; and it showed a tendency of increasing to a peak and then decreasing with the increase of each parameter（ temperature,pressure or PSt concentration）.The theoretical phase diagrams indicated that pressure has more influence in changing the binodal curve location than that of temperature.