Experimental investigation and semi-empirical modeling of mechanical behavior in Gr, GO, and rGO nanocomposites

The growing adoption of polymer nanocomposites in industry necessitates accurate prediction of their mechanical behavior and the achievement of desirable properties. This can be accomplished by developing robust theoretical models and leveraging state-of-the-art manufacturing techniques. The significance of this issue is particularly pronounced in structures where the intended purpose demands a higher weight percentage of reinforcing materials. In this research, nanocomposites with 0.075, 0.15, 0.3, 0.45, and 0.6 weight percentages of graphene (Gr), graphene oxide (GO), and reduced graphene oxide (rGO) nanoparticles in epoxy have been studied. Subsequently, the properties of the nanoparticles and nanocomposites were analyzed through Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and atomic force microscopy (AFM). According to the tensile test results, nanocomposites with GO-reinforced epoxy exhibited the highest maximum stress compared to rGO and Gr. The epoxy nanocomposite containing 0.15 weight percent GO increases the maximum stress by 15.7 percent compared to pure epoxy. The elastic modulus of the nanocomposites was calculated, with the highest result obtained for the nanocomposite containing 0.6 weight percent Gr, exhibiting a 19.7 percent increase compared to epoxy. It was also seen that the Halpin-Tsai model did not fit well with the experimental elastic modulus values at high weight percentages. Therefore, a semi-empirical modified model was presented, considering the impact of agglomeration and the Krenchel orientation factor. The experimental data from other articles and the present study validated the results of this model.