Photothermal healing of a glass fiber reinforced composite interface by gold nanoparticles

Abstract

The formation of microcracks especially in the interfacial region is a critical problem for fiber reinforced composites. Repairing the microcracks before catastrophic failure of the materials takes place is a promising solution to achieve long lifetime operation. In this context, a novel method is demonstrated for interfacial healing of glass fiber reinforced composites using the photothermal effect of gold nanoparticles (Au NPs). Au NPs were successfully dispersed into the interfacial region of a glass fiber reinforced composite. Once the interfacial damage occurred, a laser could be used to illuminate Au NPs to generate a large amount of heat through the photothermal effect. This would melt the resin and form mechanical interlocking between the fiber and PMMA to create a new interface. It has been confirmed by a micro bond test that the composite containing Au NPs has healing ability with a maximum healing efficiency of 98.5% under optimized conditions. The mechanism of the interfacial healing was also investigated and it is found that the density of Au NPs and irradiation intensity play key roles in the healing process.