Prying or pushing? The dispersion mechanism of amphiphilic molecules on graphene in aqueous solution: A molecular dynamics simulation

•The effects of amphiphilic molecules as dispersants in aqueous solution of graphene dispersion were explored by molecular dynamics simulations.•Two graphene-dispersion mechanisms were presented, and the relationship between the structure and the mechanism was described.•The optimal mechanical operation to obtain high dispersing yield to molecules with different dispersion mechanism was suggested.