Carbon-Based Reinforcement in Epoxy Composites: A Comprehensive Review

Mainly carbon-based substances, such as carbon fibers, carbon nanotubes, graphene, and reduced graphene oxide, have been demonstrated to be excellent reinforcements for epoxy composites to overcome the intrinsic brittleness, low fracture toughness, and limited fatigue resistance of neat epoxy.Also, these reinforcements not only add to the load transfer and crack resistance, but they also bring many other multifunctional improvements, especially electrical and thermal conductivity.The present review contains an extensive range of discussions about the mechanical, thermal, interfacial, and fatigue behavior of various carbon-reinforced epoxy composites.A detailed discourse of the significant processing methods and the most relevant challenges is given, particularly those relating to nanoparticle dispersion, interfacial engineering, and scalable manufacturing.This review also discusses the current trends and future directions, particularly the hybrid hierarchical composites comprising different micro-and nano-scale carbon reinforcements that may maximize structural performance and durability through smart functionality for advanced engineering applications.