Interaction of Short-Chain PFAS with Polycationic Gels: How Much Fluorination is Necessary for Efficient Adsorption?
Interaction of Short-Chain PFAS with Polycationic Gels: How Much Fluorination is Necessary for Efficient Adsorption?
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DOI：
10.1021/acsmacrolett.2c00383
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发表时间：
2022-08
影响因子：
5.8
通讯作者：
Aditya Choudhary;D. Bedrov
中科院分区：
文献类型：
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作者：
Aditya Choudhary;D. Bedrov
引入短链全氟和多氟烷基物质（PFAS）以取代遗留的PFAS化合物，结果证明，它们与长链的前身一样有毒和有害，甚至更难从受污染的水源中隔离。本文采用分子动力学（MD）模拟研究了短链PFAS的代表化合物GenX在主链和交联剂氟化程度不同的聚阳离子水凝胶上的吸附机理。模拟结果表明，聚合物凝胶结构中靠近阳离子基团的氟化段为GenX的吸附提供了最有效的环境。与具有非氟化阳离子或非阳离子氟化片段的聚合物片段相比，由阳离子-亲氟片段提供的静电和疏水相互作用的组合放大了GenX分子的结合。此外，这种凝胶对GenX的选择性比其氢化类似物高。
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.