Graphene oxide as a potential carrier or remover for flotation collectors: A molecular dynamics study

Abstract

In order to explore graphene oxide (GO) as a potential carrier or remover for flotation collectors in complex environments, the study investigated the individual and competitive adsorption processes of flotation collectors on GO using molecular dynamics (MD) simulations through 2-Methylpropoxymethanedithioate (CS), a xanthate-based collector, and Diethylthiophosphate (PS), an aerofloat-based collector. The distribution of molecular conformations, center-of-mass distance calculations, radial distribution function analysis, hydrogen bonding analysis and interaction force calculations were used to conclude that when CS and PS were under competing adsorption systems, both molecules adsorb more strongly on the GO surface than under individual adsorption systems, and CS molecules could promote the adsorption of PS. Coulomb interactions between the two organic molecules were the driving force for them to show a more dispersive effect under competitive adsorption conditions, and van der Waals forces were the main reason why both molecules can adsorb on the GO surface. This work provided some theoretical implications for improving the flotation environment as well as industrial wastewater treatment.