Post-fabrication modification of forward osmosis membranes with a poly(ethylene glycol) block copolymer for improved organic fouling resistance
Post-fabrication modification of forward osmosis membranes with a poly(ethylene glycol) block copolymer for improved organic fouling resistance
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DOI：
10.1016/j.memsci.2015.04.060
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发表时间：
2015-09-15
影响因子：
9.5
通讯作者：
Elimelech, Menachem
中科院分区：
文献类型：
--
作者：
Shaffer, Devin L.;Jaramillo, Humberto;Elimelech, Menachem
为了提高对有机污染的抵抗力，需要采用简便有效的策略对正向渗透(FO)膜进行改性。抗污染的FO膜将促进FO在处理废水和盐水等高污染潜力的给水方面的商业化应用。我们报道了一种膜修饰技术，通过酰胺偶联反应在商用薄膜复合(TFC)FO膜的表面接枝了聚乙二醇(PEG)嵌段共聚物。根据在改性过程中增加聚乙二醇浓度而增加膜的亲水性和降低透水率，优化了膜的聚乙二醇改性浓度。与未改性的对照膜相比，当暴露在具有侵略性的合成废水混合物中时，改性膜表现出更好的抗有机污染能力。尽管聚乙二醇的接枝不均匀，但由于膜表面羧基结合部位的可及性有限，聚乙二醇膜仍具有抗污染性能。用这种后处理技术改性的膜的耐污染性能优于用其他方法改性的TFC-FO膜。本文报道的改性技术具有成本相对较低、易于实现、适用于商用膜等优点。(C)2015爱思唯尔B.V.保留所有权利。
Facile and effective strategies are needed to modify forward osmosis (FO) membranes for improved resistance to organic fouling. Fouling resistant FO membranes will advance the commercial implementation of FO for treating feed waters with high fouling potential, such as wastewater and brines. We report a membrane modification technique for post-fabrication grafting of a poly(ethylene glycol) (PEG) block copolymer to the surface of commercial thin-film composite (TFC) FO membranes via an amide coupling reaction. The PEG concentration for membrane modification is optimized based on increased membrane hydrophilicity and reduced water permeability that result from increasing PEG concentrations during modification. Modified membranes exhibit improved resistance to organic fouling compared to unmodified control membranes when exposed to an aggressive synthetic wastewater mixture. The fouling resistance is achieved despite the non-uniform grafting of PEG, which is attributed to the limited accessibility of carboxylic group binding sites on the membrane surface. The fouling resistance of membranes modified using this post-fabrication technique compares favorably to TFC-FO membranes modified using other procedures. The modification technique we report in this work has the advantages of being relatively inexpensive, easy to implement, and applicable to commercial membranes. (C) 2015 Elsevier B.V. All rights reserved.