Interfacial dynamics of graphene in water environments: Role of wettability and surface charges

Understanding the interactions at liquid–two-dimensional (2D) material interfaces is crucial for the manipulation, transfer, and assembly of these materials. This study integrates molecular dynamics (MD) simulations with experimental validation to elucidate the mechanisms governing water penetration at the graphene-substrate interface, with a focus on the critical roles of wettability and surface charge. On a hydrophilic surface (θ ≈ 40°) or a surface with surface charge, water molecule can permeate into the graphene-substrate interface, promoting graphene flotation and consequent delamination from the substrate. Precise control of surface charge enables effective modulation of the interfacial contact state between graphene and the substrate. Leveraging these findings, we present a novel surface charge-enhanced graphene transfer method that successfully transfers millimeter-scale graphene patterns from SiO₂ to polydimethylsiloxane (PDMS) substrates. This work provides a solid theoretical basis and a practical methodology for the precise manipulation, transfer, and assembly of 2D materials, paving the way for the fabrication of high quality 2D-material devices with clean interfaces.