Enhancement of Mechanical and Thermo-Physical Properties in CNTs/GO-Coated Carbon Fiber-Reinforced Epoxy Composites

Abstract

This study predominantly focuses on the application of carbon nanotubes (CNTs), graphene oxide (GO), and hybrid (CNTs/GO) onto carbon fibers through a spray coating process and examines the resulting impact of the coating on mechanical, tribological, and thermo-physical properties of polymer composite. The synergetic effect of two-dimensional GO and one-dimensional CNTs forms a three-dimensional network structure, resulting in significant enhancements in the mechanical and interfacial properties of fiber-reinforced polymer composites. The CNTs/GO hybrid coated carbon fiber reinforced epoxy (HCFRE) composite demonstrates superior performance in interlaminar shear strength (ILSS), flexural strength, tensile strength, and hardness, with an enhancement of 38.73%, 30.40%, 33.53%, and 32.64%, respectively, compared to carbon fiber reinforced epoxy (CFRE) composite. The fracture toughness, tensile, and flexural modulus of the HCFRE composite have improvements of 36.36%, 31.66%, and 57.68%, respectively, as compared to the CFRE composite. The HCFRE obtained the maximum thermal conductivity with a 44.44% increment compared to the CFRE composite. The tribological tests comprise four distinct sliding frequencies (6, 8, 10, and 12 Hz) and normal loads (30, 40, 50, and 60 N) with a consistent stroke length of 1.5 mm. Worn-out surfaces are studied by scanning electron microscope (SEM) images. For the HCFRE, the specific wear rate was decreased by 42.84% compared to the CFRE composite. As the normal load increases, the friction coefficient also increases, whereas it decreases with sliding frequencies. © 2025 John Wiley & Sons Ltd.