荷负电中空纤维膜的制备、微结构调控及渗透性能研究

Preparation,microstructure regulation and permeability investigation of negative-charged hollow fiber membrane

以聚偏氟乙烯(PVDF)和苯乙烯-马来酸酐钠盐(SMA钠盐)为原料进行共混,经热致相分离技术制备"PVDF/SMA钠盐"中空纤维共混超滤膜,重点考察SMA钠盐的添加量对铸膜液体系成膜过程、膜微结构、亲水性和渗透性能的影响规律.结果表明,随着SMA钠盐添加量的增加,膜截面由球中带网结构逐渐转变为蜂窝孔结构,表明SMA钠盐具有非稀释剂的功效.同时,SMA钠盐与PVDF链段之间发生缠结并沉积在固化的PVDF表面以及膜孔内部,阻碍了PVDF的结晶从而降低了膜外皮层厚度,并且提高了膜表面的致密度、荷电性、亲水性,从而提高了渗透性能.当PVDF/SMA钠盐质量比为5/1时,膜纯水渗透率为1284 L/(m^(2)·h·MPa),对牛血清蛋白(BSA)的截留率高达96.1%,渗透率恢复率为84.2%.

In this work,polyvinylidene fluoride(PVDF)and styrene-co-maleic anhydride-Na(SMA-Na)were used to prepare PVDF/SMA-Na ultrafiltation membrane.The influence of SMA-Na on the membrane formation process,microstructure regulation,hydrophilicity and permeability was investigated.The results showed that with the increase of SMA-Na,the microstructure changed from network on spherulite to cellular pore,which indicated the non-dilute function of SMA-Na.In addition,the entanglement of segments between PVDF and SMA-Na and its deposition on both PVDF matrix and the inside of pore hindered the PVDF crystallization,decreased the thickness of skin-layer,and at the same time increased the density of skin-layer,charge and hydrophilicity.They all increased the permeability.When the mass ratio of PVDF/SMA-Na is 5/1,the pure water permeability reached 128.4 L/(m^(2)·h·MPa),the rejection of BSA is as high as 96.1%and permeability recovery rate is 84.2%.