Interphase of polydopamine hollow nanoparticles and its effects on the interface performance of CFRP

Recently, nanotechnology has been widely applied on the surface of carbon fiber (CF) to enhance the interface between fibers and resin, improving the overall performance of Carbon Fiber-Reinforced Polymers (CFRPs). Among various emerging nanomaterials, hollow nanoparticles with large specific surface areas and internal hollow qualities are expected to bring a new design to the optimization of the CFRP interface, but have not attracted much attention yet. In this paper, with the mixture of tetraethyl orthosilicate (TEOS) and dopamine in water, ethanol, and ammonia as modifiers, an interphase consisted of hollow polydopamine nanoparticles was successfully constructed on the fiber surface. The interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the composite (CF–PH/EP) improved to 100.56 MPa and 101.68 MPa, respectively. Those were significantly higher than those of the untreated composite (CF/EP) and the composite modified with the common poly(dopamine)/silica nanoparticles (CF-PS/EP). Besides, the impact toughness of the CF–PH/EP was simultaneously improved, 69 % and 22 % higher than that of CF-EP and CF-PS/EP.