Study of the structure and electrical properties of chemically reduced graphene/polyvinyl alcohol composite films

Thin films of composites of chemically reduced graphene oxide (rGO) and polyvinyl alcohol (PVA) were prepared by simple solution-mixing technique followed by filtration or evaporation. The as-obtained composite rGO/PVA films were characterized by using optical microscope, gloss meter, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The different glossiness of the upper and lower surface of the films prepared by filtration and evaporation, combined with the section SEM images indicated that the thin films have a gradient layered structure, and the distance between the layers increases from the bottom to the top surface of the thin film obtained by filtration, and decreases for the film obtained by evaporation. Such a structure gives the films anisotropic swelling and electrical conduction properties which may find practical applications in electrodes and multifunctional composites.