A study on graphene nanoplatelet dispersion methods and their effects on coating abrasion resistance and surface properties

This comprehensive study delves into the impact of graphene nanoplatelet (GNP) dispersion methods on the performance of epoxy coatings, aiming to optimize their mechanical and physical properties for enhanced durability and functionality. By meticulously examining the abrasion resistance, surface roughness, and water contact angle of nanocomposite coatings, this research sheds light on the intricate relationship between nanoparticle dispersion and coating performance. Employing advanced characterization tools such as Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and optical microscopy, the study evaluates the uniformity of GNP dispersion across different methods, including ultrasonication (US), High -Speed Dispersion (HSD), Hand Mixing, and Dual Asymmetric Centrifuge (DAC). The findings reveal that the ultrasonication method significantly outperforms others in enhancing abrasion resistance, evidenced by the lowest mass loss of 0.014 g in the US group, compared to the control group without GNPs, which exhibited a mass loss of 0.052 g. This superior performance is attributed to the highfrequency sound waves of ultrasonication, which create micro-turbulence that effectively deagglomerates GNPs, resulting in a more uniform distribution. The study also investigates the surface properties of the coatings, noting that GNPs contribute to a smoother finish both before and after abrasion tests. This is particularly evident in coatings where GNPs are dispersed through HSD and US methods, which show significantly lower post-abrasion surface roughness compared to the control. The study also highlights the complexities of GNP integration within the epoxy matrix, noting potential trade-offs in physical properties such as impact resistance and pendulum hardness. This is likely due to GNPs interfering with the cross-linking process during curing, especially when dispersed in certain components of the epoxy. Hardness measurements indicate that the choice of dispersion medium (part A vs. part B) significantly influences the composite's mechanical properties, with part A specimens showing better performance. Therefore, this research underscores the importance of selecting the right dispersion technique for incorporating GNPs into epoxy coatings. This balanced approach necessitates careful consideration of the dispersion method, GNP load, and the interaction between GNPs and the epoxy components, ultimately guiding the development of more resilient and high-performing epoxy coatings.