Studying the adsorption mechanisms of nanoplastics on covalent organic frameworks via molecular dynamics simulations

Shengcong Shang; Youxing Liu; Minghui Liu; Yichao Bai; Xinyu Wang; Bin Wu; Jianyi Chen; Jichen Dong; Yunqi Liu

doi:10.1016/j.jhazmat.2021.126796

Studying the adsorption mechanisms of nanoplastics on covalent organic frameworks via molecular dynamics simulations

J Hazard Mater. 2022 Jan 5:421:126796. doi: 10.1016/j.jhazmat.2021.126796. Epub 2021 Jul 31.

Authors

Shengcong Shang¹, Youxing Liu¹, Minghui Liu¹, Yichao Bai¹, Xinyu Wang¹, Bin Wu¹, Jianyi Chen², Jichen Dong¹, Yunqi Liu¹

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
² Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: chenjy@iccas.ac.cn.

PMID: 34388925
DOI: 10.1016/j.jhazmat.2021.126796

Abstract

Covalent organic frameworks (COFs) with well-defined supramolecular structures and high surface-area-to-volume ratio have received extensive attention on their adsorption of contaminants from micro- to nano-size. Here, we studied the adsorption mechanisms of three typical nanoplastics (NP), including polyethylene (PE), nylon-6 (PA 6), and polyethylene terephthalate (PET) on chemically stable COFs (TpPa-X, X = H, CH₃, OH, NO₂ and F) by molecular dynamics simulations. Depending on molecular structure and surface composition, two distinct interactions-electrostatic interaction and van der Waals (vdW) interaction-are identified to be responsible for the adsorption of different NP pollutants on TpPa-X. The vdW interaction is dominant during the adsorption process, while polar groups in polymers and COFs can enhance the adsorption because of the electrostatic interaction. Compared with other functional COFs, we found that TpPa-OH shows the strongest adsorption with the NP pollutants employed in this study. This work reveals the COF-polymer adsorption behavior and properties at atomic scale, which is crucial to the development of promising COF materials to deal with NP pollution.

Keywords: Adsorbents; Covalent organic frameworks; Molecular dynamics simulation; Nanoplastics.