Harnessing the potential of coal-derived graphene oxide/epoxy nanocomposites: Enhancing thermal conductivity and fracture toughness

The choice of precursor material significantly influences the properties of graphene oxide (GO), thereby providing its adaptability across diverse applications. Coal, with its distinctive molecular structure characterized by graphene-like domains and aliphatic side chains, as well as abundant impurities and heteroatoms featuring specific functional groups, emerges as a promising precursor. Employing a recently developed facile one-pot process for synthesizing semianthracite coal-derived GO (AC-GO), we have, in this study, explored its potential as a nanofiller in an epoxy matrix, resulting in AC-GO-enriched nanocomposites. The main purpose of the project was to introduce AC-GO within the epoxy matrix to enhance its thermal conductivity and fracture resistance by enhancing interfacial interactions. Our findings indicate remarkable enhancements in thermal conductivity (0.646 Wm^-1K^-1 at 1.0 wt% loading) and fracture toughness (6.7 MPam^1/2 at 0.8 wt% loading) within AC-GO loaded nanocomposites, with these improvements being 255 % and 215 %, respectively, over those for the epoxy matrix. Remarkably, they surpass those achieved with graphite-derived GO (Gr-GO) by approximately 112 % and 76 %, respectively. Enhancing thermal conductivity and fracture toughness in epoxy nanocomposites is vital for effective heat dissipation and durability, making them ideal for high-performance electronics, aerospace, and automotive applications. These improvements can be attributed to the enhanced interactions between oxygen moieties located at the periphery of AC-GO and the fundamental epoxy-amine hardener system within the resin formulation, fostering electron acceptor–donor interactions. Furthermore, we introduce a new figure of merit (FOM) that accurately captures the combined role of thermal conductivity and fracture toughness. It is shown that this FOM can serve as a useful design tool for selecting an optimal nanofiller loading for targeted applications. The findings of our paper highlight the versatility and unique attributes of AC-GO, offering promising opportunities for applications in the industrial engineering, owing to their outstanding interfacial properties.