Qiao Wang, Rui Xu, Fusheng Zha, Long Xu, Bo Kang, Heming Han
{"title":"Molecular insights into the adsorption behavior of PFAS on montmorillonite, polyethylene, and polypropylene: A molecular dynamics study","authors":"Qiao Wang, Rui Xu, Fusheng Zha, Long Xu, Bo Kang, Heming Han","doi":"10.1016/j.compgeo.2025.107461","DOIUrl":null,"url":null,"abstract":"<div><div>Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that pose significant challenges for subsurface containment and remediation. In this study, molecular dynamics simulations were employed to investigate the adsorption behavior of three representative PFAS compounds, including fluorotelomer alcohol (FTOH), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), on montmorillonite, polyethylene (PE), and polypropylene (PP), which are commonly encountered in geotechnical and barrier system materials. Simulation results indicate that FTOH exhibits the highest adsorption density on the polymeric matrices (PP and PE), whereas PFOS and PFOA preferentially adsorb onto montmorillonite. The strong adsorption of PFOS and PFOA on montmorillonite is primarily governed by electrostatic interactions between their oxygenated and sulfonate functional groups and the negatively charged clay surfaces. In contrast, adsorption on PE and PP is dominated by van der Waals interactions with the PFAS fluorocarbon tails. The overall adsorption affinity follows the trend: montmorillonite > PP > PE, consistent with calculated interaction energies and mean squared displacement analyses. Additionally, the molecular structure of PFAS, specifically chain length and functional group composition, was found to significantly influence adsorption dynamics. These insights enhance the mechanistic understanding of PFAS retention and mobility in geomaterials, providing a foundation for improved modeling and risk assessment of contaminant transport in geotechnical systems.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"187 ","pages":"Article 107461"},"PeriodicalIF":5.3000,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computers and Geotechnics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0266352X25004100","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS","Score":null,"Total":0}
引用次数: 0
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that pose significant challenges for subsurface containment and remediation. In this study, molecular dynamics simulations were employed to investigate the adsorption behavior of three representative PFAS compounds, including fluorotelomer alcohol (FTOH), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), on montmorillonite, polyethylene (PE), and polypropylene (PP), which are commonly encountered in geotechnical and barrier system materials. Simulation results indicate that FTOH exhibits the highest adsorption density on the polymeric matrices (PP and PE), whereas PFOS and PFOA preferentially adsorb onto montmorillonite. The strong adsorption of PFOS and PFOA on montmorillonite is primarily governed by electrostatic interactions between their oxygenated and sulfonate functional groups and the negatively charged clay surfaces. In contrast, adsorption on PE and PP is dominated by van der Waals interactions with the PFAS fluorocarbon tails. The overall adsorption affinity follows the trend: montmorillonite > PP > PE, consistent with calculated interaction energies and mean squared displacement analyses. Additionally, the molecular structure of PFAS, specifically chain length and functional group composition, was found to significantly influence adsorption dynamics. These insights enhance the mechanistic understanding of PFAS retention and mobility in geomaterials, providing a foundation for improved modeling and risk assessment of contaminant transport in geotechnical systems.
期刊介绍:
The use of computers is firmly established in geotechnical engineering and continues to grow rapidly in both engineering practice and academe. The development of advanced numerical techniques and constitutive modeling, in conjunction with rapid developments in computer hardware, enables problems to be tackled that were unthinkable even a few years ago. Computers and Geotechnics provides an up-to-date reference for engineers and researchers engaged in computer aided analysis and research in geotechnical engineering. The journal is intended for an expeditious dissemination of advanced computer applications across a broad range of geotechnical topics. Contributions on advances in numerical algorithms, computer implementation of new constitutive models and probabilistic methods are especially encouraged.