Adhesion strength of glass/epoxy composite embedded with heat-treated carbon black on the surface

The surface of a glass/epoxy composite material was embedded with oxidized carbon black by heat treatment to enhance the adhesion strength of the glass/epoxy composite structure. Quantitative chemical bonding analysis with X-ray photoelectron spectroscopy (XPS) was conducted to observe the chemical binding states of the surface of the carbon black particles with heat treatment. The morphological effects of the carbon black on the surface of the composite were observed using SEM and AFM. The surface free energies and lap shear strengths of the glass/epoxy adhesive joints whose adherends were embedded with oxidized carbon black were investigated in terms of the heat-treatment conditions and the amount of embedding. From the experimental results, embedding the heat-treated carbon black particles on the composite surface was found to greatly improve the adhesion strength of the composite due to the increased oxidation radicals on the carbon black surface.