In this study, C/SiOC and C/SiO₂ composites were prepared by using carbonaceous microspheres with different surface functional groups. Carbonaceous microspheres based on hydrothermal reaction of glucose contains hydroxyl group, while the surface carboxyl group increases after NaOH etching. The hydroxyl group increases the oxygen-enriched structural units of SiOC ceramics, and the C spheres are closely enwrapped in SiOC matrix after pyrolysis at 900 °C. However, the interfacial reaction of surface carboxyl with Si–OH results in the formation of cristobalite SiO₂, and C spheres are not only encased inside the SiOC matrix, but also dispersed outside of SiOC ceramics. After removal of C via calcination at 500 °C for 5 h, C/SiOC and C/SiO₂ composites are transformed into amorphous SiO₂ and cristobalite SiO₂, respectively. The thermogravimetric analysis indicates the oxidation resistance of SiOC is superior to that of C and SiO₂.

在这项研究中，使用具有不同表面官能团的碳质微球制备了C / SiOC和C / SiO ₂复合材料。基于葡萄糖的水热反应的碳质微球含有羟基，而经NaOH蚀刻后表面羧基增加。羟基增加了SiOC陶瓷的富氧结构单元，并且在900°C的热解后C球紧密包裹在SiOC基质中。但是，表面羧基与Si-OH的界面反应导致形成方石英SiO ₂，并且C球不仅包裹在SiOC基质内部，而且分散在SiOC陶瓷外部。在500°C下煅烧5 h除去C后，C / SiOC和C / SiO ₂复合材料分别转变为无定形SiO ₂和方石英SiO ₂。热重分析表明，SiOC的抗氧化性优于C和SiO ₂。