Department Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States.
ACS Macro Lett. 2022 Sep 20;11(9):1123-1128. doi: 10.1021/acsmacrolett.2c00383. Epub 2022 Aug 29.
The short-chain per- and polyfluorinated alkyl substances (PFAS), introduced to replace the legacy PFAS compounds, turned out to be as toxic and harmful as their longer-chain predecessors and even harder to sequester from contaminated water sources. In this work, molecular dynamics (MD) simulations are employed to investigate the adsorption mechanism of GenX, a representative compound for short-chain PFAS, on a polycationic hydrogel with various extents of fluorination in its backbone and cross-linkers. Simulations indicate that the presence of fluorinated segments next to cationic groups in the polymer gel structure provides the most efficient environment for GenX adsorption. The combination of electrostatic and hydrophobic interactions offered by the cationic-fluorophilic segments amplifies the binding of GenX molecules compared to polymer segments with nonfluorinated cationic or noncationic fluorinated segments. Moreover, such a gel demonstrates high selectivity toward GenX against its hydrogenated analogue.
短链全氟和多氟烷基物质（PFAS）被引入以替代传统的 PFAS 化合物，结果证明它们与长链 PFAS 化合物一样具有毒性和危害性，甚至更难从受污染的水源中隔离出来。在这项工作中，我们采用分子动力学（MD）模拟来研究 GenX（一种短链 PFAS 的代表性化合物）在带有不同程度氟化的骨架和交联剂的聚阳离子水凝胶上的吸附机制。模拟表明，在聚合物凝胶结构中紧邻阳离子基团的氟化片段为 GenX 的吸附提供了最有效的环境。阳离子亲氟片段提供的静电和疏水相互作用的结合，相较于没有氟化阳离子或非阳离子氟化片段的聚合物片段，增强了 GenX 分子的结合。此外，这种凝胶对 GenX 表现出了对其氢化类似物的高选择性。
