Surface hydrophilization of microporous polypropylene membrane by the interfacial crosslinking of polyethylenimine
Surface hydrophilization of microporous polypropylene membrane by the interfacial crosslinking of polyethylenimine
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DOI：
10.1016/j.memsci.2009.03.023
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发表时间：
2009-07
影响因子：
9.5
通讯作者：
Yunfeng Yang;L. Wan;Zhi‐Kang Xu
中科院分区：
文献类型：
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作者：
Yunfeng Yang;L. Wan;Zhi‐Kang Xu
为赋予聚丙烯微孔膜持久的表面亲水性，采用常压介质阻挡放电（DBD）等离子体预处理，并结合界面交联法制备了聚丙烯微孔膜。首先将市售的聚乙烯亚胺（PEI）涂覆在MPPM上，然后依次与对二氯二甲苯交联并与碘甲烷季铵化以形成永久带正电荷的层。采用拉伸试验、FT-IR/ATR、XPS、FESEM等手段对膜表面的物理和化学变化进行了表征。通过水接触角和纯水通量的测量，评价了改性MPPM的表面亲水性。此外，还详细研究了表面电荷对蛋白质过滤的影响，包括通量下降和蛋白质透过。结果表明，DBD等离子体处理的最佳时间为30 s。在界面交联过程中，通过调节PEI的浓度在1.0 ~ 15 g/L之间，可以方便地控制MPPM的增重。表面亲水性可显著增强且持久，其特点是水接触角急剧减小，纯水通量成倍增加，稳定性测试。蛋白质过滤的结果表明，所获得的高度亲水性和带电的膜表面是抗蛋白质污染。此外，几乎100%的蛋白质透过率表明MPPM的微滤特性没有改变。
To endow microporous polypropylene membrane (MPPM) with durable surface hydrophilicity, a facile interfacial crosslinking approach was developed, combined with a pretreatment by dielectric barrier discharge (DBD) plasma at atmospheric pressure. The commercially available polyethylenimine (PEI) was coated on MPPM firstly and was sequentially crosslinked with p-xylylene dichloride and quaternized with iodomethane to form a permanently positively charged layer. The physical and chemical changes of the membrane surface were characterized by tensile test, FT-IR/ATR, XPS, and FESEM. The surface hydrophilicity of the modified MPPMs was evaluated by water contact angle and pure water flux measurements. Besides, the influence of surface charge on protein filtration involving flux decline and protein transmission was also investigated in detail. It is found that the optimal time of DBD plasma treatment is ∼30s. Mass gain for the MPPMs during the interfacial crosslinking can be controlled conveniently by adjusting the PEI concentration from 1.0 to 15g/L. The surface hydrophilicity can be significantly enhanced and is durable, characterized by the sharp decrease of water contact angle, the double increase of pure water flux and the stability test. The results of protein filtration suggest that the obtained highly hydrophilic and charged membrane surface is resistant to protein fouling. Furthermore, almost 100% of protein transmission indicates that the microfiltration characteristic of MPPMs is unchanged.