Mechanical-thermal synergy in three-dimensional reduced graphene oxide-boron nitride dual networks enhanced tribological property of epoxy composites

The insufficient dispersion and random orientation of nanofillers in composite materials fundamentally constrain the enhancement of their tribological properties. To address these inherent limitations, a strategy was developed to assemble graphene oxide (GO) and hexagonal boron nitride (h-BN) into three-dimensional graphene‒boron nitride hybrid (3DGB) architecture via directional freeze-casting, achieving controlled alignment of these components. The sheet-sheet integration of h-BN and graphene nanosheets facilitates structural stabilization of the 3DGB network through interfacial stress redistribution mechanisms, concurrently improving the fracture resistance characteristics. The fabricated 3DGB serves as an optimized framework substrate for epoxy resin (EP) composites in the resin transfer molding (RTM) method, yielding substantial improvements in the tribological properties while achieving synergistic enhancements in both the load-bearing capacity and interfacial adhesion. Comparative analysis demonstrated that the properties of the 3DGB/EP composites were enhanced in combination with those of the pristine epoxy. Specifically, their tensile strength and thermal conductivity increase by 37.5% and 33%, respectively, compared with those of pristine epoxy. Notably, 3DGB significantly increased the tribological performance of the epoxy, as evidenced by a 72.1% reduction in the kinetic friction coefficient and a 90.12% decrease in the specific wear rate. This strategy establishes a novel paradigm for the hierarchical design of high-performance composites and offers new insights into the integration of multicomponent two-dimensional (2D) fillers and tribology-based multifunctional composites.