Methane Hydrate Formation in the Confined Nanochannel of Graphene-Mica Slits: Insights from Molecular Dynamics Simulation Study

Abstract

The impact of hydrophilic and hydrophobic surfaces and their confined space on the nucleation and growth of gas hydrates is an important topic in hydrate formation research. This study employed molecular dynamics simulations to investigate the nucleation and growth mechanisms of methane hydrate (MH) within the confined space between graphene and mica. The results demonstrate that MH formation is influenced by the methane mole fraction and the pore size of the graphene-mica nanochannel. Higher methane mole fractions led to an increased number of MH cages. Methane molecules were adsorbed onto the graphene surface, while the water molecules accumulated on the mica surface due to the hydration properties of K⁺ cations. Furthermore, methane cannot penetrate the hydrated structures of K⁺ on the mica surface, leading to the formation of stable MH cages in the central region of the graphene-mica nanochannel. This study reveals the nucleation and growth mechanisms of MH within the confined space formed by graphene and the mica surface. These findings are significant for advancing the understanding and control of gas hydrate formation on hydrophilic and hydrophobic surfaces.