CA/PSf共混超滤膜的制备及性能研究

Preparation and properties of CA/PSf blend ultrafiltration membrane

以聚砜(PSf)为基膜材料,醋酸纤维素(CA)为共混膜材料,N,N-二甲基乙酰胺(DMAc)为溶剂,去离子水为凝固浴,采用非溶剂致相分离法(NIPS法)制备CA/PSf共混平板超滤膜.综合考察了共混膜有机物溶出量,铸膜液聚合物浓度和共混比以及不同凝固浴组成对膜结构、水通量、水接触角、孔隙率、蛋白质截留率的影响.结果表明:相对于传统的以聚乙烯吡咯烷酮(PVP)作为添加剂的共混膜,使用CA作为添加剂,共混膜有机物溶出量大幅降低.随着CA含量的增加,共混膜孔隙率逐渐增大,亲水性增加.另外,随着凝胶浴中溶剂含量的增大,共混膜纯水通量不断降低,BSA截留率逐渐升高,膜形态结构变得更加致密.

The CA/PSf blend membrane were prepared through the method of non-solvent induced phase separation （NIPS） by using polysulfone as membrane material,cellulose acetate （CA） as additive,N,Ndimethyl acetamide （DMAc） as solvent and deionized water as coagulation bath.The effects of different solid contents and mixture ratio of casting solution and different composition of coagulation bath on the microstructure and performances of blend membrane were investigated.The result shows that compared with the traditional blending membrane that using polyvinylpyrrolidone （PVP） as additive,the dissolution out amount of organic compounds in the blend membranes was greatly reduced by using CA as additive;The porosity is negatively correlated with the solid content,but positively correlated with the contents of CA.In addition,the water contact angle of the membrane decreases gradually with the increase of CA content.The pure water flux of blend membrane decreases continuously with the increase of solvent content in the coagulation bath,meanwhile,the retention of BSA solution increases gradually,and the membrane morphology become denser.