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This study explores the effect of different graphene contents on the mechanical behaviour, tensile and flexural properties, and the electrochemical performance of cross-layered glass-reinforced aluminium (GLARE) laminates. Results show that the mechanical properties of GLARE with different graphene contents are similar but not identical. The mass fraction of graphene (0 wt.%–1.0 wt.%) is calculated from the total mass of adhesive. As the graphene content increases (0 wt.%–1.0 wt.%), flexural strength peaks in the presence of 0.5 wt.% graphene, but tensile strength continues to increase. When the graphene mass ratio is 1.0 wt.%, the maximum tensile strength is 245.45 MPa. When the graphene mass ratio is 0.5 wt.%, interlaminar shear strength and flexural strength are 19.06 and 260.22 MPa, respectively, which correspond to different span–thickness ratios of 8/1 and 32/1. This graphene mass ratio indicates the best three-point flexural performance of graphene-reinforced GLARE. This study further explains the enhancement mechanism through fracture surface observation. Graphene with a mass ratio of 0.5 wt.% maximises the flexural strength whilst maintaining a strong GLARE electrochemical performance. At scanning speeds of 40, 80, and 100 mV/s, the specific capacitance values are 1.76, 2.47, and 2.88 F/g, respectively. According to quantum tunnelling theory, graphene can form a conductive network when it is dispersed in a resin matrix. This theory reveals the reason why 0.5 wt.% graphene platelet-modified GLARE has good electrochemical properties. [ABSTRACT FROM AUTHOR]

Graphene platelets (electrically conductive 2D filler) and rubber nanoparticles (0D soft filler) can work together to develop electrically conductive and toughened epoxy composite adhesives. In this study, complementing effect between graphene platelets (GnPs) and rubber nanoparticles (RnPs) within an epoxy matrix is reported. In the 3‐phase composite adhesive, the 2D graphene platelets form global conductive network and rubber nanoparticles provide a viscoelastic phase inside the epoxy, both complementing each other to develop electrically conductive and toughened epoxy composite adhesives. Fracture toughness (K1c) and critical strain energy release rate (G1c) of the epoxy were augmented by 422% and 872%, respectively by adding 1 wt% RnPs and it recorded electrical percolation threshold at 0.78 vol% GnP. Also, the Young's modulus and strength of epoxy/1 wt% RnP composite were promoted from 1.57 to 2.32 GPa when 1 wt% GnP is added. Scanning electron microscopy analysis was conducted to investigate the toughening mechanism of epoxy/RnP/GnP and epoxy/GnP composites. Lap shear strength tests on epoxy composite adhesives confirm the reinforcement effect of GnPs and toughness effect of RnPs. [ABSTRACT FROM AUTHOR]

This work investigated the effect of graphene nanoplatelets (GNPs) on the water absorption and impact resistance of fibre-reinforced metal laminates (FMLs) under hygrothermal and salt spray environments. Containing GNPs of 0.1, 0.3, 0.5 and 1.0 wt%, the resulting nanocomposite FMLs were investigated for 28 days of aging in the environments. The salt-spray environment was found to pose a more serious effect on FMLs than the hygrothermal environment. The addition of GNPs at 0.3 wt% effectively reduced the water absorption of FMLs by 57.6% whilst improving their impact resistance by 150.6% in comparison with pure FML in the case of treatment by the salt-spray environment. The water absorption reduction is caused by GNPs creating a tortuous path for diffusion of water molecules and restricting the intermolecular motion of the epoxy molecules. The impact resistance improvement can be attributed to GNPs improving the modulus and crack-resistance of the epoxy matrix and thus the interfacial bonding of FMLs. [ABSTRACT FROM AUTHOR]