Graphene-modified polymer composites for ballistic and impact protection: A comprehensive review with design rules

Abstract

Graphene, a two-dimensional nanomaterial has emerged as a potential material in the development of the new state of the art ballistic and impact resistant material due to its high tensile strength, Young’s modulus and energy dissipation capacity. This literature review critically summarizes the past 20 years in graphene-based nanocomposites customised to protective applications, which connects basic relations between structure and properties and multi-scale performance in high strain-rate environments. The specific focus is also put on interfacial toughening systems, processing, functionalization, and dispersion control, which determine improved stiffness, toughness, and impact energy absorption at ultra-low loadings (less than 1 wt.%). The review also draws a comparative insight against the standard Kevlar, UHMWPE, and carbon-fiber systems with an emphasis on the effects of graphene in minimising back-face signature (BFS), and depth of penetration (DoP). The review also combines both experimental findings and computational models to demonstrate failure modes, scale-transfer issues and nacre-inspired structures that can use the layered morphology of graphene to provide better crack deflections and energy dissipation. The aspects of environmental durability in extreme temperatures, moisture and salt fog environment and the new multifunctionalities that include EMI shielding and thermal management are also discussed and presented. Nevertheless, despite these promising results, the area has remained limited in the aspects of mass-scale, affordable, manufacture of defect free graphene, effective & uniform dispersion at the industrial scale, and the final performance confirmation in realistic service conditions. Shedding light on the potential opportunities and challenges in scaling the processing, quality assurance, and hybrid structural designs of graphene nanocomposites into next-generation lightweight armour systems in defence, aerospace, and automobile industry, the review offers a broad overview of the critical gaps in knowledge and recommends coherent roadmaps to support the extrapolation of the nanocomposites.