Fabrication and characterization of graphene based film

Large area, freestanding graphene papers fabricated from 2D graphene nanosheets with optimized microstructure, graphene sheet alignment and superior properties have a wide range of functional applications. In this paper, we propose a novel approach to fabricate graphene film by Electro-spray deposition (ESD), which is considered as the preparation for a roll-to-roll industrial production of the further. Expanded graphite, as the raw materials, was dispersed into N-Methyl-2-pyrrolidone (NMP) which is used as the feeding solution for ESD. It is also shown that high-shear mixing and high ultra-sonication of graphite powder in NMP solvent result in large-scale exfoliation, giving good dispersions of graphene nanosheets. The fabrication of the film with different thicknesses is based on ESD onto the surface of a heated aluminum foil at around 140°C. Brunauer-Emmett-Teller method is used to test the surface area of raw material, which has been reported to reach 1200 m
²
/g. Raman spectroscopy and scanning electron microscope (SEM) are used to characterize the microstructure and morphology of the film, contributing to the optimization of electrospray's parameters. Joule heating was utilized to quantify thermal conductivity of the film.