Chelation of the mercury ions by polyethyleneimine: Atomistic molecular dynamics study

TL;DR

This study uses molecular dynamics simulations to explore how polyethyleneimine (PEI) can chelate mercury ions in water, revealing its capacity to bind multiple Hg2+ ions and informing water purification strategies.

Contribution

It provides atomistic insights into PEI-mercury interactions and demonstrates PEI's potential for effective mercury ion chelation in water treatment.

Findings

A single PEI molecule with ten amino groups can coordinate up to four Hg2+ ions.

PEI-Hg2+ complexes are stable according to DFT calculations.

Molecular dynamics reveal the microscopic structure of chelation complexes.

Abstract

Contamination of water by heavy metal ions represents a significant environmental concern. Among various remediation methods, chelation has proven to be an effective technique in water treatment processes. This study investigates the chelating properties of linear polyethyleneimine (PEI) and its complexation with divalent mercury ions (Hg2+) in aqueous solution. Atomistic molecular dynamics (MD) simulations were carried out using the OPLS/AA force field to examine the microscopic structure of PEI-Hg2+ complexes. PEI chains of varying lengths were considered, and it was found that a single linear PEI molecule containing ten amino groups is capable of coordinating up to four Hg2+ ions. The stability of the resulting complexes was further supported by density functional theory (DFT) calculations.