Abstract: Micro porous cellulose acetate (CA) membranes were prepared by the supercritical CO2 phase inversion method using acetone and dimethyl formamide as solvents. The morphology of the membranes was characterized by scanning electron microscope (SEM) and the water flux of membranes was measured as well. The effect of affinity between solvent and CO2，CA concentration，CO2 pressure and temperature，holding pressure time and depressurization rate on the performance of the membrane was investigated. It was found that acetone was a suitable solvent for the preparation of the membrane with homogeneous structure. Moreover，the water flux of the membrane was reduced as the pore size decreased with increasing CA concentration. The water flux increased and reached a maximum value，then decreased with the increase of pressure as well as temperature. However，holding pressure time and depressurization rate had negligible influence on the water flux of the membrane. The membrane had a water flux as high as 30 L∙m-2∙min-1 when prepared with CA concentration of 10 %，15 MPa，45 ˚C，holding pressure time 45 min，and rapid depressurization rate.

摘要： 以超临界CO2为非溶剂，丙酮和N, N-二甲基甲酰胺（DMF）为溶剂，制备了乙酸纤维素（CA）微孔膜，采用扫描电镜表征膜的微观形态并测定了膜的纯水通量，考察了溶剂与CO2的亲和性、CA质量分数、成膜压力、成膜温度、保压时间和卸压速度等因素对膜形态及性能的影响。实验结果表明，以丙酮为溶剂可制备出表观形态均一完整的膜；随着CA质量分数的增加，膜孔径变小，膜的水通量迅速降低；随着成膜压力、成膜温度的升高，膜水通量均先增加后减小；保压时间及卸压速度对膜水通量的影响较小。当CA质量分数为10 %时，在成膜压力为15 MPa，成膜温度为45 ˚C，保压45 min，快速卸压的操作条件下，微孔CA膜的水通量可达30 L·m-2·min-1。