Versatile and High-Throughput Polyelectrolyte Complex Membranes via Phase Inversion
Versatile and High-Throughput Polyelectrolyte Complex Membranes via Phase Inversion
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DOI：
10.1021/acsami.9b02115
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发表时间：
2019-05-01
影响因子：
9.5
通讯作者：
Shull, Kenneth R.
中科院分区：
文献类型：
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作者：
Sadman, Kazi;Delgado, David E.;Shull, Kenneth R.
通过可扩展和可持续的方法构建的高通量过滤膜是节能分离的理想选择。通常，这些标准很难相互协调。聚合物膜可以提供高通量，但在加工步骤中经常涉及有机溶剂。许多聚合物膜在有机介质中的溶解度也限制了它们在溶剂过滤中的应用。在本工作中，我们报道了一种简单、高通量的聚电解质复合物（PEC）膜的水处理方法，该方法在各种水环境和有机环境中具有可控的孔隙率和稳定性。PECs是由带相反电荷的聚合物链组成的材料，可以在水环境中形成固体，但可以溶解在能够破坏聚合物间离子对的非常特殊的盐溶液中。利用盐诱导的溶解和随后的络合物的重组，可以快速合成纳米至微孔膜，这种膜类似于传统的溶剂相转化技术得到的膜。由于环境的低介电常数，PECs在有机溶剂中保持稳定，这增强了静电相互作用，使其适用于广泛的水和溶剂过滤应用。在这里，我们阐明了如何操纵聚合物相行为来行使形态控制，测试了水和溶剂过滤的膜性能，并量化了PECs在相关条件下的机械稳定性。
High-flux filtration membranes constructed through scalable and sustainable methods are desirable for energy-efficient separations. Often, these criteria are difficult to be reconciled with one another. Polymeric membranes can provide high flux but frequently involve organic solvents in processing steps. Solubility of many polymeric membranes in organic media also restricts their implementation in solvent filtration. In the present work, we report a simple and high throughput aqueous processing approach for polyelectrolyte complex (PEC) membranes with controllable porosity and stability in various aqueous and organic environments. PECs are materials composed of oppositely charged polymer chains that can form solids in aqueous environments, yet which can be dissolved in very specific salt solutions capable of breaking the interpolymer ion pairs. By exploiting the salt-induced dissolution and subsequent reformation of the complex, nano- to microporous films are rapidly synthesized which resemble membranes obtained through conventional solvent-phase inversion techniques. PECs remain stable in organic solvents because of the low dielectric constant of the environment, which enhances electrostatic interactions, making them suitable for a wide range of water and solvent filtration applications. Here, we elucidate how the polymer-phase behavior can be manipulated to exercise morphological control, test membrane performance for water and solvent filtration, and quantify the mechanical stability of PECs in relevant conditions.