Multiscale simulation on wettability of graphene

Abstract

The concept of wettability

i.e. the degree of spreading water over the solid surface, has been applied to regulate chemo-physical reactions in the field of heterogeneous catalyst, corrosion resistance, self-cleaning and water harvesting. However, experimental barriers such as crystallites defects and airborne contaminants have hindered an understanding of intrinsic wettability of materials. Theoretical methods also have been challenge in interpreting the wettability because of its dependency on experimental measurements as references. A quantum mechanics/molecular mechanics (QM/MM) calculation was performed to simulate the interfacial interactions between water and graphene

in addition, two phase thermodynamics (2PT) was implemented to analyze thermodynamic energies such as the entropy and the Helmholtz free energy. The physical concept of work of adhesion was theoretically calculated to pursue a contact angle (CA), in virtue of Young-Dupre equation. A wettability of multilayered graphene (~ $87^\circ CA$) was reasonably reproduced, then, a wettability of single layer graphene (~ $97^\circ CA$) was theoretically verified. The interfacial energy between water and graphene was partitioned into van der Waals, electrostatic interactions, which could realize the interpretation of a real system graphene with various number of layers, heteroatom dopants and textured surfaces. The research would provide a new approach to understand the wetting/dewetting phenomena at an atomic level and extend the atomic/molecular simulation field by giving a sense of how to design the system of interest.