Controlling the self-assembly of perfluorinated surfactants in aqueous environments
Controlling the self-assembly of perfluorinated surfactants in aqueous environments
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DOI：
10.1039/d1cp00049g
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发表时间：
2021-04-14
影响因子：
3.3
通讯作者：
Alexandridis, Paschalis
中科院分区：
文献类型：
--
作者：
Dong, Dengpan;Kancharla, Samhitha;Alexandridis, Paschalis
全氟烷基和多氟烷基表面活性物质（PFAS）在环境中的释放在美国和世界范围内引起了极大的关注。PFAS两亲物从水性介质中的螯合可能受到其形成堵塞吸附剂材料中的孔的胶束的强烈倾向的限制，使得大部分活性表面不可接近。采用实验和模拟相结合的方法研究了全氟辛酸铵（PFOA）胶束在水溶液中的结构，重点研究了乙醇添加对PFOA胶束形成和结构的影响。PFOA胶束结构紧凑，形状略呈椭圆形，在纯水中随着乙醇含量的增加而变得更加分散，在高乙醇浓度的水溶液中破碎成较小的PFOA簇。实验和模拟都观察到随着乙醇浓度的增加，从助表面活性剂到助溶剂行为的转变，而后者也提供了关于如何用其他添加剂实现助溶剂条件的见解。对如何调节PFAS表面活性剂在水中自组装的更好理解可以告知PFAS在环境中的命运和运输以及PFAS从水介质中的螯合。
Surface active per- and polyfluoroalkyl substances (PFAS) released in the environment generate great concern in the US and worldwide. The sequestration of PFAS amphiphiles from aqueous media can be limited by their strong tendency to form micelles that plug the pores in the adsorbent material, rendering most of the active surface inaccessible. A joint experimental and simulation approach has been used to investigate the structure of perfluorooctanoate ammonium (PFOA) micelles in aqueous solutions, focusing on the understanding of ethanol addition on PFOA micelle formation and structure. Structurally compact and slightly ellipsoidal in shape, PFOA micelles in pure water become more diffuse with increasing ethanol content, and break into smaller PFOA clusters in aqueous solutions with high ethanol concentration. A transition from a co-surfactant to a co-solvent behavior with the increase of ethanol concentration has been observed by both experiments and simulations, while the latter also provide insight on how to achieve co-solvent conditions with other additives. An improved understanding of how to modulate PFAS surfactant self-assembly in water can inform the fate and transport of PFAS in the environment and the PFAS sequestration from aqueous media.