Brush‐like nanostructured graphene oxide‐enabled interface engineering for enhancing mechanical properties of glass fiber/epoxy laminated composites

Abstract Graphene oxide (GO) is preferred for addressing the issue of interfacial debonding in fiber‐reinforced composites. Herein, a brush‐like nanostructured GO was fabricated by grafting aliphatic diamine onto the basal plane of GO nanosheets through an amine‐epoxy ring‐opening reaction, and this brush‐like nanostructured GO was subsequently coated on the surface of glass fibers. The unique brush‐like nanostructure and the appropriate size of the functionalized GO nanosheets offer both steric hindrance and electrostatic repulsion, thereby achieving the well‐dispersed GO on the fiber surface. Due to the synergistic effects of physical and chemical interactions, the composites' interfacial adhesion between fiber and matrix could be prominently enhanced. When 1,8‐octanediamine‐functionalized GO with a suitable size of 1.0–5.0 μm was incorporated, both mechanical properties and thermal stability of laminated composites were at their best, compared with pure composite. This study provides an efficient interface engineering method for the production of high‐performance fiber reinforced composites. Highlights A brush‐like nanostructure consisting of GO and aliphatic diamine is gained. Well‐dispersed GO on the fiber surface is achieved. Synergistic effect of physical and chemical interactions reinforces interface. Functionalized GO with a suitable size (1.0–5.0 μm) helps reinforce interface. Suitable GO restricts epoxy chains' mobility in glassy and rubbery regions.