  A new large-area wet transfer method to transfer graphene directly onto
UHMWPE membranes without organic-coating, thermal treatment or other mediated
substrate was developed. This method completely avoids the problems of
PMMA-residue and possible PMMA coating induced tear-off by harnessing
hydrophobic-hydrophobic interactions between graphene and UHMWPE, which is one
of most facile and cheapest transfer methods that are currently available,
especially for large-area graphene preparation and transfer. Multi-layer
sandwich structure composite membrane of graphene and UHMWPE with desired
number of layers can also be easily prepared by repeating the transfer method.
The most significant applications of this transfer method lie on that it
facilitates thin polymer membranes the possibilities to be directly observed
with high magnification by electron microscopes, such as SEM and TEM. Thus the
crystallization and phase-behavior of polymers including UHMWPE can be
investigated with real-time and in-situ morphological observations, even in the
presence of their solvent and with the need of thermal treatment. Morphologies
and mechanical properties of stretched graphene/UHMWPE layered composite
membranes were investigated, and strengthening effect of graphene on one side
and both sides was observed.
