Emerging investigator series: post-synthesis modification of reverse osmosis membranes for the enhanced separation of small neutral molecules
Emerging investigator series: post-synthesis modification of reverse osmosis membranes for the enhanced separation of small neutral molecules
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新兴研究者系列：反渗透膜的合成后修饰，以增强中性小分子的分离
DOI：
10.1039/d3ew00401e
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Weinman, Steven T.
中科院分区：
文献类型：
--
作者：
Habib, Shahriar;Wilkins, Madison A.;Weinman, Steven T.
反渗透（RO）膜普遍用于海水淡化。理想地，用于合成RO膜的界面聚合（IP）反应将在聚酰胺层内形成均匀的孔或自由体积元件结构。实际上，IP的自限性和混沌性防止RO活性层被水性反应物饱和。有机反应物上未利用的附着位点在水溶液中带负电荷，有利于RO膜的脱盐。然而，这些未反应的位点使孔结构具有相当大的自由体积孔，其允许小的中性分子（SNM）渗透通过膜。本研究的目的是减少聚酰胺层表面的自由体积空间，以提高反渗透膜的尺寸排阻性能和SNM截留率。我们假设，共轭二胺或支链多胺的合成聚酰胺层将增加交联，以促进这种改善。为了验证这一假设，商业RO膜的聚酰胺层使用碳二亚胺化学活化，随后用胺改性。然后，在微波或热水浴中热处理改性的膜。各种胺，包括1，6-二氨基己烷，1，8-二氨基辛烷，间苯二胺，和聚乙烯亚胺（10 000 MW）的影响进行了评价。 结果表明，结合胺共轭和热处理的应用显着提高SNM排斥。具体地，尿素截留率从21%增加到61%，硼截留率从23%增加到59%。
Reverse osmosis (RO) membranes are used ubiquitously for seawater desalination. Ideally, the interfacial polymerization (IP) reaction used to synthesize RO membranes would form a uniform pore or free volume element structure within the polyamide layer. In reality, the self-limiting and chaotic nature of IP prevents the saturation of the RO active layer with the aqueous reactant. Unexploited attachment sites on the organic reactant are negatively charged in an aqueous solution, facilitating the desalination apt of RO membranes. However, these unreacted sites leave the pore structure with sizeable free-volume holes which permit small, neutral molecules (SNMs) to permeate through the membrane. The goal of this research is to decrease free volume space on the surface of the polyamide layer to improve the size exclusion properties of RO membranes and SNM rejection. We hypothesize that conjugating diamines or a branched polyamine to the synthesized polyamide layer will increase cross-linking to facilitate this improvement. To test this hypothesis, the polyamide layer of a commercial RO membrane is activated using carbodiimide chemistry and subsequently modified with an amine. Then, the modified membranes are heat treated in a microwave or hot water bath. The effects of various amines including 1,6-diaminohexane, 1,8-diaminooctane, m-phenylenediamine, and polyethyleneimine (10 000 MW) are evaluated. The results show that combining the application of amine conjugation and heat treatment significantly improves SNM rejection. Specifically, urea rejection was increased from 21% to 61%, and boron rejection was increased from 23% to 59%.
影响因子：
9.5
作者：
Habib, Shahriar;Weinman, Steven T.
通讯作者：
Weinman, Steven T.
影响因子：
9.5
作者：
Grzebyk, Kasia;Armstrong, Mikayla D. D.;Coronell, Orlando
通讯作者：
Coronell, Orlando