Water/solvent mixtures released from industrial processes, especially in pharma and fine chemical synthesis or in advanced oil production, are an environmental concern, necessitating the development of efficient remediation and recycling techniques. Solvent-tolerant nanofiltration (STNF), situated between aqueous nanofiltration (NF) and solvent-resistant nanofiltration (SRNF), offers a promising solution. This study investigates the potential of using aqueous NF- and SRNF-membranes to treat water/solvent mixtures. Commercial membranes (NF270, DuraMem® 300, DuraMem® 200) and a lab-synthesized polyvinylidene fluoride (XL-PVDF NF) membrane were used to treat dimethyl sulfoxide (DMSO), acetonitrile (ACN), Isopropyl alcohol (IPA), or dimethylformamide (DMF) mixtures with water. The addition of 10% DMSO, ACN, IPA, or DMF to water significantly reduced the permeance of these NF-membranes, and an increase in temperature failed to restore the initial permeance. Changes in both viscosity and surface tension of the water/solvent solutions strongly influence the permeance of the NF-membranes. Flory-Huggins and Zimm-Lundberg theories offered an explanation for the phenomenon where solvent clusters form within the dense polymer matrix of NF-membranes upon exposure to water/solvent mixtures, resulting in decreased water permeabilities. NMR analysis identified of the presence of small amounts of solvents in the STNF-membranes, even still after prolonged exposure to pure water permeation. The results emphasize the current shortcomings of aqueous and solvent-resistant membrane chemistries in handling water/solvent mixtures. Minor solvent additions significantly modify NF membrane permeance, emphasizing the need for innovative material design, especially given the variable solvent content in industrial applications.

中文翻译：

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暴露于水/溶剂混合物对纳滤膜渗透性的强烈影响

工业过程中释放的水/溶剂混合物，特别是在制药和精细化学品合成或高级石油生产中，是一个环境问题，需要开发有效的修复和回收技术。耐溶剂纳滤（STNF）介于水性纳滤（NF）和耐溶剂纳滤（SRNF）之间，提供了一种有前景的解决方案。本研究探讨了使用水性 NF 膜和 SRNF 膜处理水/溶剂混合物的潜力。使用商用膜（NF270、DuraMem® 300、DuraMem® 200）和实验室合成的聚偏二氟乙烯（XL-PVDF NF）膜来处理二甲亚砜（DMSO）、乙腈（ACN）、异丙醇（IPA）或二甲基甲酰胺(DMF) 与水的混合物。向水中添加 10% DMSO、ACN、IPA 或 DMF 会显着降低这些 NF 膜的渗透性，并且温度升高无法恢复初始渗透性。水/溶剂溶液的粘度和表面张力的变化强烈影响纳滤膜的渗透性。 Flory-Huggins 和 Zimm-Lundberg 理论对以下现象提供了解释：暴露于水/溶剂混合物时，NF 膜的致密聚合物基质内会形成溶剂簇，导致透水性降低。 NMR 分析发现 STNF 膜中存在少量溶剂，即使在长时间暴露于纯水渗透后仍然如此。结果强调了目前水性和耐溶剂膜化学在处理水/溶剂混合物方面的缺点。少量溶剂的添加会显着改变纳滤膜的渗透性，强调创新材料设计的必要性，特别是考虑到工业应用中溶剂含量的变化。