Abstract Hierarchically porous silicon carbonitride (SiCN) was prepared using the freeze casting method with silsesquiazane (SSQZ) as a precursor. As SSQZ possesses a highly branched structure, it can provide a higher cross-linking degree than linear polysilazane and thereby, improve the structural stability. The porous SiCN can be produced without collapsing the pore structures by removing the organic groups during the pyrolysis process due to the high cross-linking degree. In this study, we used the freeze casting method to introduce macropores. In addition, the effects of glycidyl-POSS and 1,7-octadiene diepoxide as additional cross-linking agents on the formation of porous ceramics were investigated. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed that SSQZ with cross-linking agents demonstrated a higher cross-linking degree and was successfully converted to SiCN ceramics. As a result, the porous SiCN ceramics exhibited an improved structural stability, specific surface area, and pore volume.

中文翻译：

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使用硅倍半氮烷前驱体冷冻浇铸法制备分级微/中/大孔碳氮化硅陶瓷

摘要 以硅倍半氮烷（SSQZ）为前驱体，采用冷冻浇铸法制备了多级多孔碳氮化硅（SiCN）。由于 SSQZ 具有高度支化的结构，它可以提供比线性聚硅氮烷更高的交联度，从而提高结构稳定性。由于高交联度，通过在热解过程中去除有机基团，可以在不破坏孔结构的情况下生产多孔SiCN。在这项研究中，我们使用冷冻铸造方法来引入大孔。此外，还研究了缩水甘油基-POSS 和 1,7-辛二烯双环氧化物作为附加交联剂对多孔陶瓷形成的影响。傅里叶变换红外光谱和 X 射线光电子能谱分析表明，SSQZ 与交联剂表现出更高的交联度，并成功转化为 SiCN 陶瓷。结果，多孔SiCN陶瓷表现出改善的结构稳定性、比表面积和孔体积。