Wetting Properties of Defective Graphene Oxide: A Molecular Simulation Study.

In the present work, the wettability of defective graphene oxide (GO) film is studied by molecular dynamics simulations. A water droplet is deposited on the surface of a graphene oxide membrane, and the contact angle is measured by fitting the liquid⁻vapor interface. Although pristine graphene has few hydrophobic properties with a contact angle of 95°, graphene oxide presents more hydrophilic properties, due to the stronger hydrogen bonds interactions at the interface. Moreover, the introduction of vacancy defects at the graphene oxide surface decreases the wettability of graphene oxide. We find that the contact angle of graphene oxide increases from 70° to 82°, with a defective concentration from 0% to 10%. Our results will help provide a new method for controlling the wetting properties of GO and its additional capabilities in device design for applications.