The Shear Modulus Determination via Quartz Crystal Resonator for Graphene Oxide Film Prepared by Drop Casting

In this paper, the shear modulus of uniform graphene oxide (GO) film is extracted using a quartz crystal resonator (QCR). The GO film is prepared by drop-casting and vacuum filtration methods. The tunable mechanical parameters of GO film with various humidity (from 10% to 90% relative humidity) have been fully investigated. The interlayer shear modulus (∼500 MPa) of GO film by vacuum filtration shows a strengthening with increasing humidity, which is ascribed to the strong hydrogen bonding networks made up of oxygen-containing functional groups of GO film and intercalated water molecules. The interlayer shear modulus (∼27 MPa) of GO film by drop-casting displays a degraded strength. These obtained properties provide good guidance to serve the practical realization of the GO-based project.