Abstract:

Using low temperature water plasma technology, methacryloxybenzyl dimethyl ammonium chloride (DMAE) monomer was grafted on the surface of the three-channel polyvinyl chloride (PVC) hollow fiber membrane (HFMs) to enhance the membrane??s hydrophilic and antibacterial properties. The ATR-FTIR and contact angle analyses revealed that the antibacterial monomers DMAE were grafted onto the HFMs. The hydrophilicity of membranes was greatly improved, resulting in an enhanced permeation of the H₂O plasma-treated membrane was twice as high as that of the original membrane. At the same time, PVC-ir-H₂O membrane (treated by water plasma technology)exhibited excellent anti-protein absorption ability, of which adsorbing capacity for bovine serum albumin (BSA) decreased by 67% and BSA solution flux increased from 7.7 to 40 kg?m^-2?h^-1. And the BSA rejection of plasma-treated membrane remained at the same level as that of the original membrane, suggesting the membrane surface damage from plasma irradiation could be neglected. Furthermore, the surface modification on HFMs is relatively uniform along the axial direction of fibers and more environment-friendly. In static antibacterial experiments, the grafted HFMs (PVC-g-DMAE) exhibited bactericidal rate of 100% against gram-negative Escherichia coli (E. coli). In dynamic filtration, the grafted module, PVC-g-DMAE, obtained above 82% bactericidal rate in feed tank. Its E. coli solution flux with 100% rejection was increased by three times as much as that of the original one. This activation-grafting technology exhibited well prospect in application of drinking water treatment membrane module, especially small household water purifiers, arising from the facile operation, low cost, and simple.

Key words: antibacterial activity, PVC hollow fiber membrane, membrane module, low-temperature H₂O plasma, graft polymerization

摘要：

采用低温水等离子体技术，在三通道聚氯乙烯(PVC)膜表面接枝了甲基丙烯氧基苄基二甲基氯化铵(DMAE)单体，增强了膜亲水和抗菌性能。通过红外分析，表明DMAE成功接枝到了PVC膜上，水通量提高两倍，PVC-ir-H₂O膜(通过水等离子体处理的膜)对牛血清蛋白(BSA)的吸附能力下降67%，对BSA溶液的通量从7.7提高至40 kg?m^-2?h^-1，并且对BSA的截留能力不变。通过静态及动态抗菌实验，接枝后的PVC膜（PVC-g-PMAE膜）抗菌率达到100%，膜组件运行中的抗菌率也达到82%以上。在保证细菌截留率100%的同时，其渗透通量提高三倍。该膜表面修饰工程技术能实现膜表面的均一化改性，且绿色环保、操作简便、成本低，改性膜在饮用水处理领域，尤其是家用净水器中展现了很好的应用前景。

关键词: 抗菌改性, PVC中空纤维膜, 膜组件, 低温水等离子体, 表面接枝工程