A graphene/poly(vinyl alcohol) hybrid membrane self-assembled at the liquid/air interface: enhanced mechanical performance and promising saturable absorber

A liquid-air self-assembly strategy is proposed to uniformly hybridize hydrophobic graphene with amphiphilic polymer, like PVA (poly(vinyl alcohol)), in a thin membrane, where the polymer imparts aqueous-dispersion and membrane-forming abilities to the encapsulated graphene. The microstructure, transmittance and wettability of the GNS/PVA hybrid membranes are finely tunable by changing the GNS fraction. Due to strong interaction between GNSs and PVA, the GNS-incorporated hybrid membrane formed at liquid-air interface shows improved thermal stability and highly enhanced mechanical performance as compared to GNS-free PVA membrane. Also, well-distributed GNS in the transparent polymer carrier make the hybrid membrane an ideal saturable absorber in ultrafast laser systems.