The effectiveness of the membranes is largely influenced by the characteristics of the additives. This study introduces a novel approach to the fabrication of loose nanofiltration (LNF) membranes by utilizing deep eutectic solvents (DESs) as innovative pore formers. For the first time, we systematically investigated the combined effects of DES hydrophilicity and molecular mass on membrane morphology during the phase inversion process. Four distinct polysulfone (PSF)-based LNF membranes with the same nature and different hydrophilicity and molecular mass were synthesized to elucidate the thermodynamic and kinetic parameters influencing casting solution behavior. Our analysis reveals that an increase in DES molecular mass correlates with elevated thermodynamic parameters, while viscosity increases contribute to enhanced kinetic hindrance during membrane formation. Furthermore, the study demonstrates that higher hydrophilicity in DES additives not only reduces thermodynamic instability but also encourages the formation of finger-like pores throughout the membrane’s structure. The synthesized membranes exhibited superior separation performance, achieving over 86% rejection of Congo red dye and less than 3% rejection of sodium ions. These findings present a promising strategy for designing membranes with the desired performance for salt–dye separation, mitigating water waste, and improving sustainability.

中文翻译：

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通过定制低共晶溶剂添加剂的亲水性和分子量来设计松散纳滤膜：热力学和相反转动力学


膜的有效性在很大程度上受添加剂特性的影响。本研究介绍了一种利用深共熔溶剂 （DES） 作为创新造孔剂来制造松散纳滤 （LNF） 膜的新方法。我们首次系统地研究了 DES 亲水性和分子量在相转化过程中对膜形态的综合影响。合成了四种不同的基于聚砜 （PSF） 的 LNF 膜，它们具有相同的性质，但具有不同的亲水性和分子量，以阐明影响铸溶液行为的热力学和动力学参数。我们的分析表明，DES 分子量的增加与热力学参数的升高相关，而粘度的增加会导致膜形成过程中动力学障碍的增强。此外，该研究表明，DES 添加剂中较高的亲水性不仅可以降低热力学不稳定性，还可以促进在整个膜结构中形成指状孔。合成的膜表现出优异的分离性能，对刚果红染料的截留率超过 86%，对钠离子的截留率低于 3%。这些发现为设计具有所需盐-染料分离性能的膜、减少水浪费和提高可持续性提供了一种有前途的策略。