Influence of surface properties of graphene oxide/carbon fiber hybrid fiber by oxidative treatments combined with electrophoretic deposition

An effective way to prepare graphene oxide/carbon fiber hybrid fiber was proposed by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition process. Surface functional group, surface roughness, and surface morphologies of carbon fibers were examined by Fourier transform infrared spectrometer, atomic force microscopy, and scanning electron microscopy. Results showed that a uniform and thick graphene oxide films were constructed on the surface of carbon fiber. Deposition density increased by introduction of pretreatment of the carbon fiber in the electrophoretic deposition process has been shown as a possible method. Dynamic contact angle analysis results indicated that the deposition of graphene oxide significantly improved surface free energy of carbon fiber by increasing surface area and polar groups. The introduction of graphene oxide in the carbon fiber‐reinforced epoxy composites results in a 55.6% enhancement in the interfacial shear strength and confirms the remarkable improvement in the interfacial adhesion strength of the composites, and the fracture mechanism was also analyzed. Copyright © 2016 John Wiley & Sons, Ltd.