Graphene oxide (GO), as the name suggests, is composed of nanosheets of graphene modified with oxygen functional groups such as hydroxyl and epoxy groups. This material has gained greater attention due to the vast and exciting applications ranging from water purification, proton conducting membranes in fuel cells etc. The existence of both hydrophilic and hydrophobic domains on the GO sheet gives rise to a non-homogeneous interfacial region at the GO-aqueous interface. The goal of this study is to use molecular simulations to gain molecular-level understanding of the GO-liquid interface. The initial stage of this study is to evaluate the accuracy of different force fields (non-polarizable and polarizable) and potentials (three-body) in providing an accurate description of the interactions at the GO-liquid interface. Our results indicate that most of the force fields and potential fail to capture the correct interactions at this interfacial region. Hence as the next stage of the study, a new model for the GO-water interface system is being developed by the reparameterization of the force field parameters from quantum mechanical data. Many-body interactions for the GO surface, liquid water phase as well as for the interactions between the GO surface and the water phase are included in the new model. This novel model will be further used to study chemical processes such as the adsorption of organic contaminants related to the GO-liquid interface system. The results of this work will be presented and discussed.

Towards an accurate force-field for the graphene oxide – aqueous interface

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.