Can We Describe Graphene Confined Water Structures as Overlapping of Approaching Graphene–Water Interfacial Structures?

We investigate the microscopic mechanisms of the overlap of interfacial structures in confined fluids and attempt to answer the question whether the confined structures can be predicted from the original density profiles of individual solid–fluid interfaces. For that purpose, we perform (globally) isobaric–isothermal (locally, grand canonical) molecular dynamics simulations to extract not only the axial distribution functions of the water sites for the uncoupled graphene–water interfaces, but also those corresponding to the confined aqueous environments over the interplate range 8 ≤ h (Å) ≤ 28 typically at ambient conditions. We have tested two (i.e., an arithmetic and a geometric) superposition approximations for the singlet density of confined water between flat graphene plates, as well as for a combination of flat and corrugated graphene plates. The outcome of this study suggests that the answer to the title’s question is a “yes”, provided that the interplate distance h is large enough to avoid fluid geometric packing frustration.