水凝胶涂层法用于PTFE平板膜的亲水改性研究

采用戊二醛和O-羧甲基壳聚糖(OCMCS)、聚乙烯醇(PVA)在聚四氟乙烯(PVDF)平板膜内进行交联形成一层水凝胶涂层,从而对PTFE平板膜进行亲水改性。考察了反应条件对膜亲水性能的影响和膜的抗污染性能,并对膜表面进行表征。结果表明,水凝胶涂层附着在PTFE纤维表面使膜原纤维变粗,随着PVA含量的增加,改性膜的水通量先增加后减少,接触角先减小后增大,并且当PVA与OCMCS的质量比为1:1,反应时间为6 h、温度为50℃时,膜的性能为优,此时水通量(4 481±80) L/(m^2·h)、接触角57.48°。由于改性膜的表面含有羟基和氨基等官能团,使膜具备良好的抗蛋白质吸附能力;PVA与OCMCS交联形成的物质分子量大,粘附力强,使亲水涂层不易脱落。

Study on Hydrophilic Modification of PTFE Flat Membrane by Hydrogel-coating Method

Hydrophilic modification of polytetrafluoroethylene(PTFE) flat membrane was pro-crosslinked by glutaraldehyde and O-carboxymethyl chitosan(OCMCS), polyvinyl alcohol(PVA) to form a hydrogel coating on PTFE flat membrane. The effects of reaction conditions on membrane hydrophilicity and membrane anti-pollution performance were investigated, and the membrane surface was characterized. The results showed that the hydrogel coating was successfully loaded onto the surface of the PTFE hydrophobic membrane, and the membrane fibrils were thicker. With the increasing of the PVA content, the water flux of the modified membrane increased first and then decreased, while the contact angle changes on the contrary. With the 1:1 mass ratio of PVA and OCMCS, the reaction time was 6 h, and the temperature was 50 ℃, the membrane performance was optimal, the water flux and contact angle was(4 481±80) L/(m^2·h) and 57.48° respectively. Since the surface of the modified membrane contained functional groups such as hydroxyl and amino groups, the anti-protein adsorption ability of membrane was found to be increased. The molecular weight of the cross-linking product of PVA and OCMCS was large and showed strong adhesion, leading to a hydrophilic coating which was not easy to remove.