S. Moon, Z. Gu, K. Craig, T. Luo
University of Notre Dame,
United States
Keywords: polyethylene, composite films, ballistic, space applications, high strength, graphene, radiation
Summary:
This study optimized the mechanical properties of high-strength polyethylene (PE) composite films containing thermally reduced graphene oxide (TrGO) using Bayesian Optimization (BO). The films were fabricated through a hot-drawing process to achieve high molecular orientation and crystallinity (Figure 1).¹˒² The optimized films achieved exceptional tensile strengths exceeding 4.3 GPa (Figure 2). Structural analysis using X-ray diffraction (XRD) and Raman spectroscopy quantitatively revealed high crystallinity and molecular alignment within the drawn films. Besides high strength, the film can also be processed to be optically transparent. An index-matching multilayer structure improved optical transmittance, maintaining over 70 % for four-layer PE laminates compared to 83 % for the control, effectively suppressing interfacial scattering. The multilayer design was optimized to achieve a balance between mechanical strength and optical transparency. Multiple-layer ballistic panels were fabricated . Ballistic testing revealed that, at the same total thickness, panels with our films exhibited superior energy transfer efficiency than those of the control. This indicates that the added PE/TrGO layer effectively promotes stronger molecular-level interactions and energy dissipation upon impact. Beyond ballistic performance, the environmental stability of the PE/TrGO composites was further examined under simulated space conditions. Radiation resistance was systematically evaluated under extremely high exposure and dose rates (> 500 Gy s⁻¹). Even under these harsh conditions, the films retained a tensile strength above 1.5 GPa, demonstrating that these graphene-reinforced composites hold strong potential for next-generation lightweight ballistic protection and extreme space environment applications.