Effect of hydrogen gas pressure on the mechanical properties of reduced graphene oxide-HA nanocomposites

Abstract

Introduction: One of the attractive ways to synthesize graphene-hydroxyapatite (HA) nanocomposites is the hydrothermal process that results in situ synthesis of graphene-HA hybrid powders.<br /> Objective: In this study, hydrogen gas was injected into a hydrothermal autoclave with varying initial pressures in order to investigate the effect of gas pressure on the final mechanical properties of graphene-HA nanocomposites.<br /> Material and Methods: The powders obtained from the hydrothermal process were consolidated by spark plasma sintering method. The synthesized powders were evaluated by X-ray diffraction, Raman spectroscopy, and Fourier transforms infrared spectroscopy. The sintered samples were subjected to mechanical analysis by the Vickers indentation technique. <br /> Result: The findings of this study showed that increasing the pressure of hydrogen gas increased crystallinity, crystallite size, and particle size in the HA phase. Also, it increased the rate of GO reduction, increased the hardness and elastic modulus of the nanocomposites. <br /> Conclusion: The results of this study could be useful for the synthesis and applications of graphene-HA nanocomposites.