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| 基于密度泛函理论研究全氟辛酸在4种微塑料上的吸附行为 |
| Density Functional Theory Study on the Adsorption Behavior of PFOA on Four Kinds of Microplastics |
| 投稿时间：2025-02-22 修订日期：2025-03-17 |
| DOI： |
| 中文关键词: 全氟辛酸 微塑料 吸附 密度泛函理论 新污染物 |
| 英文关键词:perfluorooctanoic acid, microplastics, adsorption, density functional theory, emerging pollutant |
| 基金项目: |
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| 中文摘要: |
| 微塑料（MPs）和全氟辛酸（PFOA）同属新污染物，在环境中广泛存在，两者的吸附作用改变了单一毒性和运输途径。本文以密度泛函理论从分子层面对PFOA吸附聚乙烯（PE）、聚氯乙烯（PVC）、聚对苯二甲酸乙二醇酯（PET）和聚酰胺（PA）这4种微塑料上的行为进行研究。Hirshfeld划分的独立梯度模型（IGMH）分析和“分子中的原子”理论（AIM）拓扑分析表明PFOA通过范德华相互作用吸附在PE、PVC和PET上，通过氢键吸附在PA上，吸附能计算结果表明吸附强度由弱到强顺序依次为PE≈PVC |
| 英文摘要: |
| Microplastics (MPs) and perfluorooctanoic acid (PFOA) are both emerging pollutants that are widely present in the environment. The adsorption of the two alters the single toxicity and transport pathways. This work studied the molecular-level adsorption behavior of PFOA on four types of microplastics namely PE, PVC, PET, and PA using density functional theory. Independent gradient model based on Hirshfeld partition (IGMH) analysis and atoms-in-molecules (AIM) topological analysis revealed that PFOA adsorbed on PE, PVC, and PET primarily via van der Waals interaction and on PA through hydrogen bonds. Calculated adsorption energies indicated that the adsorption strength increased in the order: PE ≈ PVC < PET < PA. Energy decomposition analysis showed that the adsorption on PE, PVC, and PET was predominantly driven by dispersion attraction, whereas on PA, it was governed by a combination of electrostatic attraction and dispersion attraction, with some orbital interaction. Electrostatic potential analysis and atomic charge distribution provided insights into the system's charge characteristics. Energy decomposition analysis based on forcefield (EDA-FF) was used to examine the contribution of dispersion to atoms in the system. Extended transition state - natural orbitals for chemical valence (ETS-NOCV) analysis of the O?H-N hydrogen bonds in PA-PFOA revealed the existence of a certain extent of covalent interaction components. The bond energy and CVB index of hydrogen bonds suggested that the formed hydrogen bonds were of medium strength. The theoretical calculation results of this study elucidated previously reported experimental observations and offered a foundation for understanding the adsorption behavior of other perfluoroalkyl and polyfluoroalkyl substances on microplastics. |
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