During transferring graphene film using Cu etchent, its important for the film to float on liquid surface. I know PMMA makes the surface hydrophobic. Is CVD graphene film (w/o PMMA) on copper foil hydrophobic or hydrophilic?
But Gr can't float by itself.. Too much mechanical force. It will disintegrate on top of the solvent by itself, if you dont use PMMA. One of the main reason to use PMMA is also to provide mechanical rigidity to Gr during floating...