Zwitterionic bi-continuous membranes from a phosphobetaine copolymer/poly(vinylidene fluoride) blend via VIPS for biofouling mitigation
Zwitterionic bi-continuous membranes from a phosphobetaine copolymer/poly(vinylidene fluoride) blend via VIPS for biofouling mitigation
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DOI：
10.1016/j.memsci.2017.12.075
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发表时间：
2018-03-15
影响因子：
9.5
通讯作者：
Chang, Yung
中科院分区：
文献类型：
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作者：
Venault, Antoine;Hsu, Chen-Hua;Chang, Yung
由于两性离子共聚物与聚偏氟乙烯(PVDF)等常见疏水性膜材料共混时会遇到溶解性问题，因此通过原位改性将其用于抗污染膜的设计仍未得到探索。在这里，我们用2-甲基丙烯酰氧乙基磷酰胆碱和甲基丙烯酰氧乙基丁基氨基甲酸酯的共聚物克服了这个问题，称为PMBU。汽相分离法制备的PVDF膜具有高孔隙率(孔隙率为75%)和较强的双连续结构(弹性模数E>；80 Mpa)，而原始PVDF膜仍含有结节，导致膜较弱(E=67 Mpa)。在局部和映射模式下的ATR FT-IR表明，由于PMBU在1730 cm(-1)处的酯基的存在相当均匀地分布在膜的表面，所以有一个很强的信号。其亲水性得到显著改善，水化容量达到280 mg/cm(3)。因此，改性膜在与细菌溶液(大肠杆菌)接触时表现出良好的抗污染性能，并完全抑制了全血的生物污染。此外，经4次水/腐植酸过滤后，最佳膜的通量恢复率为42%，而市售亲水性PVDF膜的通量恢复率为17%。因此，本工作表明，通过原位改性可以制备出耐污染的两性离子双连续PVDF基膜。
The use of zwitterionic copolymers for the design of fouling resistant membranes by in-situ modification remains unexplored because these copolymers face solubility issues when blended with common hydrophobic membrane materials such as poly(vinylidene fluoride) (PVDF). Here, we overcame this issue using a copolymer of 2-methacryloyloxyethyl phosphorylcholine and methacryloyloxyethyl butylurethane groups, named PMBU. The resulting membranes formed by vapor-induced phase separation exhibited a highly porous (porosity of 75%) and strong (modulus of elasticity E > 80 MPa) bi-continuous structure, while the virgin PVDF membrane still contained nodules, resulting in weaker membrane (E = 67 MPa). ATR FT-IR in local and mapping modes evidenced a strong signal ascribed to the presence of ester groups of PMBU at 1730 cm(-1,) fairly well distributed at the surface of the membranes. It led to a significant improvement of their hydrophilic properties with a hydration capacity reaching 280 mg/cm(3). Consequently, the modified membranes showed excellent antifouling properties when contacted with bacterial solutions (Escherichia coli) and totally inhibited biofouling by whole blood. Furthermore, a flux recovery ratio of 42% was measured with the best membrane after 4 water/humic acid filtration cycles, while it was 17% in the same conditions with a commercial hydrophilic PVDF membrane. Hence this work demonstrates that fouling-resistant zwitterionic bi-continuous PVDF-based membranes can be prepared by in-situ modification.