美国宾西法尼亚州立大学Cremer, Paul S.团队报道了弱水合阴离子在水溶液中与聚合物结合，但不与单体结合。相关研究成果发表在2021年11月1日出版的《自然—化学》。

弱水合阴离子有助于在水溶液中溶解疏水性大分子，但含有相同化学成分的小分子暴露于这些离子时会沉淀出来。

该文中，通过系统地研究NaSCN与聚氧化乙烯低聚物和不同分子量聚合物的相互作用，解决了该明显的矛盾。光谱和计算结果表明，SCN在聚合物表面附近聚集，但不包括在单体中。这是因为SCN优先结合到大分子链的中心，在那里局部水氢键网络被破坏。研究结果揭示了离子特异性效应和疏水水合作用如何受疏水实体大小和形状调节的理论之间的联系。

附：英文原文

Title: Weakly hydrated anions bind to polymers but not monomers in aqueous solutions

Author: Rogers, Bradley A., Okur, Halil I., Yan, Chuanyu, Yang, Tinglu, Heyda, Jan, Cremer, Paul S.

Issue&Volume: 2021-11-01

Abstract: Weakly hydrated anions help to solubilize hydrophobic macromolecules in aqueous solutions, but small molecules comprising the same chemical constituents precipitate out when exposed to these ions. Here, this apparent contradiction is resolved by systematically investigating the interactions of NaSCN with polyethylene oxide oligomers and polymers of varying molecular weight. A combination of spectroscopic and computational results reveals that SCN accumulates near the surface of polymers, but is excluded from monomers. This occurs because SCN preferentially binds to the centre of macromolecular chains, where the local water hydrogen-bonding network is disrupted. These findings suggest a link between ion-specific effects and theories addressing how hydrophobic hydration is modulated by the size and shape of a hydrophobic entity.

DOI: 10.1038/s41557-021-00805-z

Source: https://www.nature.com/articles/s41557-021-00805-z