The role of graphene and its derivatives in tribology: Advances in polymer and metal matrix composites

Graphene-based materials, including monolayer graphene, reduced graphene oxide (rGO), and graphene nanoplatelets (GNPs), have emerged as transformative materials in tribology due to their exceptional combination of mechanical strength, thermal conductivity, and lubrication properties. It is essential to differentiate among these materials, as their structure and properties vary significantly. Still, the commercialization of graphene-based composites has been hindered by scalability, weak interfacial adhesion, and poor dispersion. This review systematically evaluates recent advances in graphene and its derivatives -reinforced composites, focusing on their mechanical and tribological properties. It's interesting to consider that while graphene's two-dimensional structure allows heat dissipation and self-lubrication, how layer thickness, functionalization, and graphene dispersion affect composite performance remains largely unexplored. Additionally, graphene's and its derivatives’ potential to improve environmental sustainability through energy savings and lightweight characteristics highlights its growing significance in energy-efficient systems and green manufacturing. The proposed novel insights aim to address existing gaps by investigating improved functionalization strategies that enhance interfacial bonding, creating hybrid graphene composites with specific applications, and understanding the composites’ long-term stability under various operating conditions. Enhancing the incorporation of graphene into polymer matrices could lead to innovations in biomedical tribology, specifically in joint replacement and bio-lubrication.