Adsorption Mechanism of Perfluorooctanoate on Cyclodextrin-Based Polymers: Probing the Synergy of Electrostatic and Hydrophobic Interactions with Molecular Dynamics Simulations
Adsorption Mechanism of Perfluorooctanoate on Cyclodextrin-Based Polymers: Probing the Synergy of Electrostatic and Hydrophobic Interactions with Molecular Dynamics Simulations
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DOI：
10.1021/acsmaterialslett.2c00168
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发表时间：
2022-05-02
影响因子：
11.4
通讯作者：
Bedrov, Dmitry
中科院分区：
文献类型：
--
作者：
Choudhary, Aditya;Dong, Dengpan;Bedrov, Dmitry
全氟烷基和多氟烷基物质（PFAS）对天然水资源的污染已经影响到全世界数百万人，并突出了开发新型有效吸附材料的需求。我们演示了如何原子分子动力学（MD）模拟可以用来提供分子尺度的洞察力的作用，静电和疏水相互作用的全氟辛酸酯（PFOA）表面活性剂，一个突出的长链PFAS，在水中的聚合物为基础的网络上的吸附。具体而言，全氟辛酸铵盐的吸附已被研究的β-环糊精（CD）的网络交联与decororobiphenyl连接作为一个例子的吸收材料，已经证明有效的PFAS吸附。成对相互作用的检查揭示了涉及静电和疏水相互作用的双管齐下的吸附机制的重要性。铵离子在CD链段上的吸附促进了PFOA表面活性剂的阴离子头基的吸引，而氟化连接体为PFOA尾部提供了额外的疏水吸引力，并且与烃相比，网络对PFOA具有更高的亲和力。这些竞争性相互作用导致PFOA主要吸附在CD空腔之外，PFOA主要与氟化连接体相互作用。我们证明，模拟使用“如果“的情况下是一个强大的方法来推断不同的相互作用中的PFAS吸附的作用
Contamination of natural water resources by per- and polyfluorinatedalkyl substances (PFAS) has affected millions of people around the world andemphasized the need for development of novel and effective adsorbent materials. Wedemonstrate how atomistic molecular dynamics (MD) simulations can be used toprovide molecular scale insight into the role of electrostatic and hydrophobicinteractions on the adsorption of the perfluorooctanoate (PFOA) surfactant, aprominent longer-chain PFAS, on a polymer-based network in water. Specifically, theadsorption of ammonium perfluorooctanoate salt has been investigated on the beta-cyclodextrin (CD) network cross-linked with decafluorobiphenyl linkers as anexample of an absorbent material that has already demonstrated efficient PFASadsorption. Examination of pairwise interactions reveals the importance of the dualpronged adsorption mechanism involving both electrostatic and hydrophobicinteractions. The adsorption of ammonium counterions on the CD segmentsfacilitates attraction of the anionic headgroup of the PFOA surfactant, whilefluorinated linkers provide an additionalhydrophobic attraction for the PFOA tail as well as higher affinity of the network toward PFOA in comparison withhydrocarbons. These competing interactions result in PFOA adsorption primarily outside of the CD cavity with the PFOA tailmostly interacting withfluorinated linkers. We demonstrate that simulations using"what if"scenarios are a powerful approachto infer the role of different interactions in the adsorption of PFAS