空气暴露时长对聚醚砜微滤膜结构及性能的影响

Effects of air exposure time on the structure and properties of polyether sulfone microfiltration membrane

以聚醚砜为原料,聚乙二醇为致孔剂,采用汽相诱导致相分离(vapor-induced phase separation,VIPS)制备聚醚砜(polyether sulfone,PES)微滤膜,考察了空气暴露时长对膜孔结构、分离性能和抗污染性能的影响。随着暴露时长的增加,膜表面孔先增多,后减少;膜断面则由指状孔变成海绵孔(0~100 s),再变为连通性较差的蜂窝孔(100~200 s);水通量随着暴露时长的增加从3514 L·m^(-2)·h^(-1)增加到7764 L·m^(-2)·h^(-1)后,又下降至10 L·m^(-2)·h^(-1);在100 s内,膜对酵母浸粉的截留率稳定在95%以上,随后急剧下降至1%。优选得到的膜对腐殖酸和牛血清白蛋白均表现出较好的抗污染能力。研究结果揭示了暴露时长对膜性能影响的规律,对采用VIPS工艺制造微滤膜具有一定的参考性。

Polyether sulfone(PES)microfiltration membranes were prepared by the vapor phase induced phase separation(VIPS)with PES as raw material and polyethylene glycol(PEG)as a pore-forming agent.The effects of air exposure time on membrane pore structure,separation performance and anti-pollution performance were investigated.The research was found that the surfaces of membranes pores increase first and then decrease with the extension of exposure time.The cross section of the membrane changed from finger-like pores to sponge pores(0~100 s)and then to honeycomb pores(100~200 s)with the poor connectivity.The water flux increased from 3514 L·m^(-2)·h^(-1)to 7764 L·m^(-2)·h^(-1),and then decreased to 10 L·m^(-2)·h^(-1)with the increases of exposure time.Within 100 s,the rejection rate of yeast extract stabilizes at more than 95%,and then decreases sharply to 1%.The optimized membrane showed good resistance to humic acid and bovine serum albumin.The influence of exposure time on membrane performance was systematically studied,and the work has certain guiding significance for the manufacture of microfiltration membrane by VIPS process.