Influence of water molecule on absorption performance between benzene and graphene: Molecular simulation and theoretical model

Abstract

In field of drug delivery, graphene is a potential material as drug carrier due to its large specific surface area and excellent chemical stability. Many kinds of drug molecules can be adsorbed on graphene surface through single or multiple benzene ring structures in drug molecules. Graphene loaded with drug molecules needs to be transported to the lesion site through blood. The content of water molecules in blood accounts for 92%. Therefore, the influence of water molecule on adsorption performance cannot be ignored. Here, the influence and mechanism of water molecule on the adsorption properties between benzene molecule and graphene is studied. The adsorption models of benzene molecule on graphene surface in vacuum and water environments are established, respectively. The adhesion energy, adhesion force and stable adsorption position of benzene molecule in two environments are analyzed by molecular dynamics simulation and potential function theory. Moreover, a model of preadsorption of a single water molecule on graphene surface is further presented, which explains the reason of the difference in adsorption performance in vacuum and water environment from the perspective of energy. The preadsorption of water molecule on graphene surface promotes the adsorption of benzene molecule.