A comparative study on the effect of graphene and TiO2 nanoparticle embedding sites on the mechanical performance of glass fiber/epoxy composites

This study investigates the influence of nanoparticle embedding sites on the mechanical properties of glass fiber/epoxy composites, focusing on the cooperative effects of graphene nanoplatelets (GNPs) and titanium dioxide (TiO 2 ). While these composites are chosen for industrial applications, their mechanical properties often require enhancement to match more advanced alternatives. To optimize performance, nanoparticles were either dispersed within the epoxy matrix or coated onto the glass fiber surfaces using a polystyrene tuning agent. Five distinct hybrid configurations were fabricated and subjected to tensile and flexural testing. Results indicated that the optimal placement of nanoparticles depends heavily on the type of load. The highest tensile properties were achieved when TiO 2 nanoparticles were dispersed within the epoxy matrix while GNPs were coated on the surface of glass fibers. Under this formation, the tensile strength, elastic modulus, and absorbed energy increased by 43.2%, 41.2%, and 58.8%, respectively, compared with the neat composite. Conversely, the flexural properties exhibited the most significant improvement when both types of nanoparticles were dispersed in the epoxy matrix. In this case, the flexural strength, flexural modulus, and absorbed energy increased by 62.8%, 14.5%, and 52.3%, respectively, relative to the neat composite. FESEM analysis confirmed that the enhancements were driven by mechanisms such as crack pinning, crack deflection, and GNP exfoliation. However, the agglomeration of nanoparticles was found to cause catastrophic reductions in mechanical integrity. This research demonstrates that the strategic positioning of layered and particulate nanoparticles is a critical factor in designing high-performance hybrid multiscale composites.