聚四氟乙烯微孔膜亲水性与抗污性的关系研究

摘要

The relationship between the hydrohilicity and antifouling performance of polytetrafluoroethylene (PTFE) microporous membrane in cross-flow filtration is determined. The effects of the sulfonic group ( -SO3H) on the water contact angle, Zeta potential, static absorption of bovine serum albumin (BSA) , and water flux were studied by scanning electron microscopy, Fourier-transform infrared spectros-copy,and surface potential analysis of solid surface after introducing -SO3H onto the surface of a PTFE membrane. The Zeta potential is negative, owing to the absorption of electronegative ion onto the hydro-phobic PTFE membrane. The PTFE membrane shows abundant static absorption of BSA and obviously decreased water flux, which demonstrates a weak antifouling property. However, the PTFE/P(AA-co-NaSS) composite membrane shows excellent antifouling performance because the introduction of -SO3H makes the absorption of electronegative ions and BSA difficult. The electrostatic repulsion between the membrane and BSA is enhanced because the Zeta potential becomes more negative with increased -SO3-from the ionization of-SO3H, which improves the antifouling performance.%探讨错流过滤中聚四氟乙烯微孔膜亲水性与抗污性的关系.在聚四氟乙烯(PTFE)膜表面引入磺酸基(-SO3H),通过扫描电镜(SEM)、傅里叶红外光谱(FTIR)、固体表面电位分析仪(SurPASS)等研究-SO3H含量对膜亲水性、Zeta电位、牛血清蛋白(BSA)静态吸附量及水通量的影响.结果表明:疏水的PTFE膜易吸附负离子,Zeta电位＜0,BSA吸附量高,水通量降幅大,抗污性差；经过亲水改性后,由于--SO3H的引入,膜表面不易吸附负离子,Zeta电位升高,BSA吸附量降低,水通量降幅小；随-SO3H含量增加,膜Zeta电位因-SO3H电离而降低,与负电性BSA之间的静电斥力增强,抗污性进一步提高.