Nano enhanced GFRP composites: a comparative assessment of graphene and halloysite additives under low-velocity impact loading

Abstract This study investigates the effects of graphene nanoplatelets and halloysite nanotubes on the low-velocity impact behavior of glass fiber–reinforced polymer composites manufactured via ultrasonic-assisted dispersion and vacuum infusion. Unfilled, graphene filled (0.5, 1.0, and 1.5 wt%), and halloysite nanotube filled (0.5, 1.0, and 1.5 wt%) composites were fabricated and tested using a drop weight impact system to assess their peak contact force, deformation response, and overall energy absorption characteristics. Graphene reinforced samples exhibited a substantial increase in peak contact force, particularly at 1 wt%, indicating enhanced stiffness and load transfer due to the high aspect ratio and superior intrinsic strength of graphene. However, the 1.5 wt% graphene specimens showed a reduction in maximum force. In contrast, Halloysite nanotube filled composites displayed a more progressive and ductile response. The 1 wt% HNT sample achieved the best balance between load bearing capacity and displacement, demonstrating improved energy dissipation through micro crack deflection, crack bridging, and nanotube pull-out mechanisms. Microscobic analyses confirm that graphene is more effective for increasing peak load, whereas halloysite nanotubes provide superior impact resilience and damage tolerance. Overall, low nano filler loadings (0.5–1 wt%) significantly enhanced the impact performance of polymer based composites, while excessive filler content led to dispersion-related performance losses.