In this study, the effect of the argon, nitrogen, and hydrogen gases on the final properties of the reduced graphene oxide- hydroxyapatite nanocomposites synthesized by gas injected hydrothermal method was investigated. Four samples were synthesized, which in the first sample the pressure was controlled by volume change at a constant concentration. In subsequent samples, the pressure inside the autoclave was adjusted by the injecting gases. The initial pressure of the injected gases was 10 bar and the final pressure considered was 25 bar. The synthesized powders were consolidated at 950 °C and 2 MPa by spark plasma sintering method. The final samples were subjected to Vickers indentation analysis. The findings of this study indicate that the injection of argon, hydrogen, and nitrogen gases improved the mechanical properties of the nanocomposites. Injection of gases increased the crystallinity and particle size of hydroxyapatite, and this increase was greater for nitrogen gas than for others. Injection of these gases increased the rate of graphene oxide reduction and in this case the effect of nitrogen gas was greater than the others.

中文翻译：

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氩，氢和氮气对还原的氧化石墨烯-羟基磷灰石纳米复合材料特性影响的比较

在这项研究中，研究了氩气，氮气和氢气对通过注水水热法合成的还原氧化石墨烯-羟基磷灰石纳米复合材料最终性能的影响。合成了四个样品，在第一个样品中，压力通过恒定浓度下的体积变化来控制。在随后的样品中，高压釜内的压力通过注入气体进行调节。注入气体的初始压力为10 bar，考虑的最终压力为25 bar。通过火花等离子体烧结法将合成的粉末在950℃和2MPa下固结。将最终样品进行维氏压痕分析。这项研究的发现表明，注入氩气，氢气和氮气可改善纳米复合材料的机械性能。气体的注入增加了羟基磷灰石的结晶度和粒径，并且氮气的增加大于其他的增加。注入这些气体增加了氧化石墨烯的还原速率，在这种情况下，氮气的影响大于其他气体。