Imparting Selective Fluorophilic Interactions in Redox Copolymers for the Electrochemically Mediated Capture of Short-Chain Perfluoroalkyl Substances
Imparting Selective Fluorophilic Interactions in Redox Copolymers for the Electrochemically Mediated Capture of Short-Chain Perfluoroalkyl Substances
复制标题
DOI：
10.1021/jacs.2c10963
复制
发表时间：
2023-03-21
影响因子：
15
通讯作者：
Su，Xiao
中科院分区：
文献类型：
--
作者：
Santiago，Anaira Roman;Yin，Song;Su，Xiao
随着全氟烷基和多氟烷基物质（PFAS）在世界各地的法规越来越多，了解分子水平的相互作用，驱动其结合的功能吸附材料是关键有效的PFAS去除水流。随着传统长链PFAS的逐步淘汰，短链PFAS的出现对材料设计提出了重大挑战，因为它们具有更高的流动性和亲水性，并且常规处理方法的去除效率低。在这里，我们展示了如何合作的分子相互作用是必不可少的目标短链PFAS（从C4到C7），通过定制结构单元，以提高亲和力，同时调节捕获和释放PFAS的电化学控制。我们报告了一类新的氟化氧化还原活性胺官能化共聚物，以利用短链PFAS结合的亲氟和静电相互作用。我们结合联合收割机分子动力学（MD）模拟和电吸附，以阐明设计师的功能基团，使亲和力对短链PFAS的作用。分子动力学模拟得到的优先相互作用系数与实验趋势密切相关：聚乙烯醇增强了PFAS的总体吸收，促进了疏水性较低的短链PFAS（C≤ 5）的捕获，而仲胺基团提供的静电相互作用足以捕获疏水性较高的PFAS（C≥ 6）。诱导电场的加入对最短的PFAS表现出有利的动力学增强，并增加了从电极释放的可逆性。这些共聚物与电化学分离的集成显示出在环境相关条件下去除这些污染物的潜力，同时消除了对化学再生的需要。
With increasing regulations on per- and polyfluoroalkyl substances (PFAS) across the world, understanding the molecular level interactions that drive their binding by functional adsorbent materials is key to effective PFAS removal from water streams. With the phaseout of legacy long-chain PFAS, the emergence of short-chain PFAS has posed a significant challenge for material design due to their higher mobility and hydrophilicity and inefficient removal by conventional treatment methods. Here, we demonstrate how cooperative molecular interactions are essential to target short-chain PFAS (from C4 to C7) by tailoring structural units to enhance affinity while modulating the electrochemical control of capture and release of PFAS. We report a new class of fluorinated redox-active amine-functionalized copolymers to leverage both fluorophilic and electrostatic interactions for short-chain PFAS binding. We combine molecular dynamics (MD) simulations and electrosorption to elucidate the role of the designer functional groups in enabling affinity toward short-chain PFAS. Preferential interaction coefficients from MD simulations correlated closely with experimental trends: fluorination enhanced the overall PFAS uptake and promoted the capture of less hydrophobic short-chain PFAS (C≤ 5), while electrostatic interactions provided by secondary amine groups were sufficient to capture PFAS with higher hydrophobicity (C≥ 6). The addition of an induced electric field showed favorable kinetic enhancement for the shortest PFAS and increased the reversibility of release from the electrode. Integration of these copolymers with electrochemical separations showed potential for removing these contaminants at environmentally relevant conditions while eliminating the need for chemical regeneration.