双凝胶剂中第一凝胶剂对聚砜中空纤维膜结构的影响

Effect of the First Coagulant in the Double-Coagulant System on the Membrane Structure of PSF Hollow Fiber Membrane

采用双凝胶浴法研究了第一凝胶剂(水、甘油、乙醇、丙酮和正己烷)对聚砜中空纤维膜近外表面处结构的影响。结果表明,第一凝胶剂的延迟时间越长,所制得的膜的近外表面处越疏松,铸膜液溶剂与第一凝胶剂之间溶解度参数差值(Δδm)越大,制得的皮层结构越致密;第一凝胶剂瞬时分相时,易产生大孔结构,但当第一凝胶剂为非水溶性的正己烷时,尽管第一凝胶剂延迟分相而第二凝胶剂瞬时分相也产生大孔膜结构。

The effect of the first coagulant (water, glycerol, ethanol, acetone and n-hexane) on the membrane structure near the external surface of PSF hollow fiber membrane was studied using the double-coagulant method. Longer was the delay time of the first coagulant looser was the membrane structure near the external surface. Larger was the difference of solubility parameter(Δδ_m) between the solvent in the dope solution and the first coagulant denser was the membrane structure near the external surface. Instantaneous demixing with first coagulant was intended to lead to the macrovoids structure. Delayed demixing with first coagulant (n-hexane) and instantaneous demixing with second coagulant also resulted in the macrovoids.