Relating performance of thin-film composite forward osmosis membranes to support layer formation and structure
Relating performance of thin-film composite forward osmosis membranes to support layer formation and structure
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DOI：
10.1016/j.memsci.2010.11.014
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发表时间：
2011-02-01
影响因子：
9.5
通讯作者：
Elimelech, Menachem
中科院分区：
文献类型：
--
作者：
Tiraferri, Alberto;Yip, Ngai Yin;Elimelech, Menachem
渗透驱动的膜工艺具有处理受损水源、淡化海水/咸水以及可持续生产能源的潜力。开发适合这些工艺的膜对于将技术推进到商业上可行至关重要。在此，系统研究了薄膜复合膜支撑层结构对正渗透性能的影响。该膜由选择性聚酰胺活性层组成，该活性层通过界面聚合形成在通过相分离制造的聚砜支撑层之上。通过系统地改变聚砜层铸造过程中使用的条件，产生了一系列具有不同结构的支撑层。研究了溶剂质量、涂料聚合物浓度、织物层润湿和浇铸叶片浇口高度在支撑层结构形成中所起的作用。使用 1 M NaCl 汲取溶液和去离子水进料，产生了 4 至 25 L m(-2) h(-1) 范围内的水通量，并且具有一致的高脱盐率 (>95.5%)。分析了膜结构与性能之间的关系。这项研究证实了这样的假设：最佳的正向渗透膜由混合结构支撑层组成，其中一层薄薄的海绵状层位于高度多孔的大空隙顶部。为了制造高性能正渗透膜，活性层传输性能和支撑层结构特性都需要优化。 (C) 2010 Elsevier B.V. 保留所有权利。
Osmotically driven membrane processes have the potential to treat impaired water sources, desalinate sea/brackish waters, and sustainably produce energy. The development of a membrane tailored for these processes is essential to advance the technology to the point that it is commercially viable. Here, a systematic investigation of the influence of thin-film composite membrane support layer structure on forward osmosis performance is conducted. The membranes consist of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation. By systematically varying the conditions used during the casting of the polysulfone layer, an array of support layers with differing structures was produced. The role that solvent quality, dope polymer concentration, fabric layer wetting, and casting blade gate height play in the support layer structure formation was investigated. Using a 1 M NaCl draw solution and a deionized water feed, water fluxes ranging from 4 to 25 L m(-2) h(-1) with consistently high salt rejection (>95.5%) were produced. The relationship between membrane structure and performance was analyzed. This study confirms the hypothesis that the optimal forward osmosis membrane consists of a mixed-structure support layer, where a thin sponge-like layer sits on top of highly porous macrovoids. Both the active layer transport properties and the support layer structural characteristics need to be optimized in order to fabricate a high performance forward osmosis membrane. (C) 2010 Elsevier B.V. All rights reserved.