文青波

Phase evolution of SiOC-based ceramic nanocomposites derived from a polymethylsiloxane modified by Hf- and Ti-alkoxides

发布时间：2021-09-04

点击次数：

影响因子：3.78

DOI码：10.1111/jace.16817

发表刊物：Journal of the American Ceramic Society

摘要：SiOC/HfO2-based ceramic nanocomposites with in situ formed HfO2 nanoparticles were prepared via a single-source precursor (SSP) approach starting from a polymethylsilsesquioxane (PMS) modified by Hf- and Ti-alkoxides. By varying the alkyl-group of the employed Hf-alkoxides, SiOC/HfO2-based ceramic nanocomposites with different HfO2 polymorphs formed via thermal decomposition of the SSP under the same heat-treatment conditions. Using PMS chemically modified by Hf(OnBu)4, tetragonal HfO2 phase was formed after the synthesis at 1100°C in Ar, whereas both, tetragonal and monoclinic HfO2 nanocrystals, were analyzed when replacing Hf(OnBu)4 by Hf(OiPr)4. After oxidation of the synthesized nanocomposites in air at 1500°C, a facile formation of oxidation-resistant HfSiO4 (hafnon) phase occurred by the reaction of HfO2 nanocrystals with silica present in the SiOC nanocomposite matrix derived from Hf(OiPr)4-modified SSPs. Moreover the amount of hafnon is dramatically increased by the additional modification of the polysiloxane with Ti-alkoxides. In contrast, ceramic nanocomposites derived from Hf(OnBu)4-modified SSPs, almost no HfSiO4 is detected after oxidation at 1500°C even though in the case of Ti-alkoxide-modified single-source precursor.

合写作者：Qingbo Wen, Tao Li, Leonore Wiehl, Claudia Fasel, Yao Feng, Dario De Carolis, Zhaoju Yu, Qian-Gang Fu, Ralf Riedel

第一作者：Jia Sun

论文类型：期刊论文

文献类型：J

卷号：103

期号：2

页面范围：1436-1445

是否译文：否

发表时间：2020-02-01

收录刊物：SCI

发布期刊链接：https://ceramics.onlinelibrary.wiley.com/doi/full/10.1111/jace.16817