Molecular dynamics insights into polypropylene microplastics adsorption onto PDMS coated sponge

Guifang Liu; Junyi Zhao; Yuxi Zhao; Hairong Mi; Linan Zhu; Chunli Wang; Di Guan

doi:10.1016/j.envpol.2025.126733

Molecular dynamics insights into polypropylene microplastics adsorption onto PDMS coated sponge

Environ Pollut. 2025 Jun 26:126733. doi: 10.1016/j.envpol.2025.126733. Online ahead of print.

Authors

Guifang Liu¹, Junyi Zhao², Yuxi Zhao³, Hairong Mi², Linan Zhu², Chunli Wang², Di Guan²

Affiliations

¹ College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China. Electronic address: liuguifang@hrbeu.edu.cn.
² College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China.
³ Hainan International College of MUC,Minzu University of China, Hainan 572423, China.

PMID: 40581173
DOI: 10.1016/j.envpol.2025.126733

Abstract

Microplastics (MPs) pose a significant threat to the environment and human health. This study investigates the adsorption behavior of polypropylene (PP) MPs on polydimethylsiloxane (PDMS) surface using experiments and molecular dynamics (MD) simulations. We prepared a PDMS coated sponge with excellent adsorption capacity of PP, which still achieved a removal rate of 90.3% after 10 cycles of use. MD simulations revealed that PP underwent significant conformational changes during adsorption, transitioning from a three-dimensional ellipsoidal shape to a two-dimensional elliptical disk, with negligible influence from the PDMS surface hydration layer. The spontaneous adsorption process was primarily driven by van der Waals interaction between the surface of PDMS and PP, and the methyl groups of PDMS were the dominant adsorption sites for PP. These findings enriched the theory of PP adsorption based on MD simulation analysis and provided a promising adsorption material for MPs removal from aquatic environments.

Keywords: Adsorption; Hydrophobic sponge; Mechanism; Molecular dynamics; Polypropylene microplastics.