Increasing Salt Rejection of Polybenzimidazole Nanofiltration Membranes via the Addition of Immobilized and Aligned Aquaporins
Increasing Salt Rejection of Polybenzimidazole Nanofiltration Membranes via the Addition of Immobilized and Aligned Aquaporins
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DOI：
10.3390/pr7020076
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Priyesh Wagh;Xinyi Zhang;Ryan Blood;P. Kekenes-Huskey;P. Rajapaksha;Yinan Wei;I. Escobar
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文献类型：
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作者：
Priyesh Wagh;Xinyi Zhang;Ryan Blood;P. Kekenes-Huskey;P. Rajapaksha;Yinan Wei;I. Escobar
水通道蛋白是细胞膜上的水通道蛋白，对水分子具有高度特异性，同时限制污染物和小分子（如尿素和硼酸）的通过。半胱氨酸官能团安装在水通道蛋白Z上，以共价连接到聚合物膜基质上，以便蛋白质可以固定在膜上并沿流动方向排列。使用X射线光电子能谱仪（XPS）分析的深度剖析显示对应于用半胱氨酸修饰的水通道蛋白Z（Aqp-SH）的官能团的存在。Aqp-SH改性膜显示出更高的盐截留率相比，未改性的膜。对于2 M NaCl和CaCl 2溶液，从Aqp-SH膜获得的截留率为49.3 ± 7.5%和59.1 ± 5.1%。另一方面，未改性膜对2 M NaCl和CaCl 2溶液的截留率分别为0.8 ± 0.4%和1.3 ± 0.2%。此外，Aqp-SH膜没有显示出盐截留率随着进料浓度的增加而显著降低，如用其他膜观察到的那样。通过模拟研究，确定了约24%的膜孔被分散的水通道蛋白覆盖。
Aquaporins are water channel proteins in cell membrane, highly specific for water molecules while restricting the passage of contaminants and small molecules, such as urea and boric acid. Cysteine functional groups were installed on aquaporin Z for covalent attachment to the polymer membrane matrix so that the proteins could be immobilized to the membranes and aligned in the direction of the flow. Depth profiling using x-ray photoelectron spectrometer (XPS) analysis showed the presence of functional groups corresponding to aquaporin Z modified with cysteine (Aqp-SH). Aqp-SH modified membranes showed a higher salt rejection as compared to unmodified membranes. For 2 M NaCl and CaCl2 solutions, the rejection obtained from Aqp-SH membranes was 49.3 ± 7.5% and 59.1 ± 5.1%. On the other hand, the rejections obtained for 2 M NaCl and CaCl2 solutions from unmodified membranes were 0.8 ± 0.4% and 1.3 ± 0.2% respectively. Furthermore, Aqp-SH membranes did not show a significant decrease in salt rejection with increasing feed concentrations, as was observed with other membranes. Through simulation studies, it was determined that there was approximately 24% capping of membrane pores by dispersed aquaporins.