Improved performance of thin-film composite membrane with PVDF/PFSA substrate for forward osmosis process
Improved performance of thin-film composite membrane with PVDF/PFSA substrate for forward osmosis process
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DOI：
10.1016/j.memsci.2017.04.038
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发表时间：
2017-08
影响因子：
9.5
通讯作者：
Xuan Zhang;Liang Shen;Wan‐Zhong Lang;Yan Wang
中科院分区：
文献类型：
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作者：
Xuan Zhang;Liang Shen;Wan‐Zhong Lang;Yan Wang
在本工作中，将少量的亲水性全氟磺酸(PFSA)引入到聚偏氟乙烯(PVDF)基材中，以制备用于正向渗透应用的高性能薄膜复合(TFC)膜。由于PFSA的亲水性和与PVDF的良好相容性，不仅显著改善了改性膜基材的润湿性，而且通过改变PVDF/PFSA基材的膜形态，优化了膜的孔径。这两个因素有效地缓解了界面聚合过程中的水传递阻力，有利于聚酰胺(PA)层的形成，从而同时提高了TFC膜的水通量和膜的选择性。通过不同的表征手段，系统地研究了PFSA浓度对改性基材和PVDF/PFSA TFC膜整体性能的影响。因此，PVDF/PFSA TFC膜在AL-DS模式下的最佳水通量(JV)为54.4 LMH，反盐通量(JS)为10.9 GMH；在AL-FS模式下，以去离子水和1M NaC l水溶液为原料和牵伸溶液，PVDF/PFSA TFC膜的最佳JV为27.0 LMH，反盐通量为8.4 GMH。这项工作为在疏水性衬底上开发TFC膜提供了一个新的方向，使其固有的优势得到最大限度的发挥。
In this work, a small amount of hydrophilic perfluorosulfonic acid (PFSA) is incorporated into the polyvinylidene fluoride (PVDF) substrate to develop the high-performance thin-film composite (TFC) membrane for forward osmosis applications. Because of the hydrophilicity and excellent compatibility with PVDF, PFSA not only significantly improves the wettability of the modified membrane substrate, but also well optimizes the pore size by changing the membrane morphology of PVDF/PFSA substrate. These two factors effectively mitigate the water transport resistance and favor the better formation of the polyamide (PA) layer during the interfacial polymerization, thus improving both the water flux and membrane selectivity of the resultant TFC membranes simultaneously. Effects of the PFSA concentration on the overall properties of the modified substrates and corresponding PVDF/PFSA TFC membranes are systematically investigated via various characterizations. Consequently, the PVDF/PFSA TFC membrane achieves a best water flux (JV) of 54.4 LMH and a reverse salt flux (JS) of 10.9 gMH in AL-DS mode, and aJVof 27.0 LMH withJSof 8.4 gMH in AL-FS mode using deionized (DI) water and 1 M NaCl aqueous solution as the feed and draw solutions respectively. This work may provide a new orientation in developing TFC membranes on the hydrophobic substrate with its intrinsic advantages maximized.