Mechanical reinforcement while remaining electrical insulation of glass fibre/polymer composites using core-shell CNT@SiO2 hybrids as fillers

Carbon nanotubes (CNTs) have been widely used as mechanical reinforcement agents of composites. However, their aggregations, weak interfacial interaction with polymer, as well as high electrical conductivity limit their use in some especial applications. In this paper, the silicon oxide (SiO2)-coated (CNT@SiO2) core-shell hybrids with different SiO2 thickness were prepared and employed to reinforce glass fibre-reinforced bismaleimide-triazine (BT) resin (GFRBT) composites. The results indicated the mechanical properties, including tensile strength and Young's modulus increased with the increase of SiO2 thickness and CNT@SiO2 loading. Such enhanced mechanical properties were mainly attributed to the intrinsically nature of CNTs, homogeneous dispersion of the hybrids, as well as improved interfacial interaction. Meanwhile, the composites remained high electrical insulation (9.63 × 1012 Ω cm) due to the existence of SiO2 layer on CNT surface. This study will guide the design of functionalized CNTs and the construction of high-performance composites.