同时刮膜法是一种利用涂层与支撑层分离来制备高表面开孔率微孔膜的方法.本文采用同时刮膜法制备PSf微孔膜,考察了底层制膜液中聚砜的浓度、添加剂PVPK-90含量、凝胶浴温度以及PEI涂层厚度等参数对膜结构和性能的影响.结果表明,PSf溶液中聚合物浓度增大使溶液的黏度明显增大,同时膜表面凹洞数目减少,孔径减小,且水通量减少.添加剂PVP提高了孔与孔间的连通性,PSf膜的纯水通量随着PVP含量的增加而增大.提高凝胶浴温度,对膜孔隙率影响较小,但平均孔径和水通量增大.PEI层的厚度影响相分离前锋到达PEI与PSf溶液界面的时间,PEI层越厚,PSf膜表面结构就越疏松,膜孔径和水通量越大,但孔隙率反而下降.上述结果对双层刮膜法制备孔径可控高通量的微孔膜具有重要意义.
The polymer concentration,PVPK-90 concentration,coagulant temperature and coating thickness were investigated for preparation of polysulfone microfiltration membranesvia co-casting.Results indicated that increase of PSf concentration can effectively prevent the formation of concave structure in PSf surface with decrease in water permeability,pore size and porosity.Increasing PVP concentration significantly decreased the surface porosity.At higher coagulant temperature and with a thicker PEI coating,PSf membranes showed higher permeability and larger pore size.Theses results open up a new way in tailor making high flux MF membranes with a wide range of pore size.