From bulk to porous structures: Tailoring monoclinic SrAl 2 Si 2 O 8 ceramic by geopolymer precursor technique

• Published in: Journal of the American Ceramic Society Vol. 103; no. 9; pp. 4957 - 4968
• Main Authors: Zhao, Shengjian, Qin, Shaohua, Jia, Zhanlin, Fu, Shuai, He, Peigang, Duan, Xiaoming, Yang, Zhihua, Li, Daxin, Jia, Dechang, Zhang, Jie, Zhou, Yu
• Format: Journal Article
• Language: English
• Published: 01.09.2020
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.17166

Abstract In this paper, monoclinic SrAl 2 Si 2 O 8 ceramics with porous structures were prepared based on ion‐exchanged geopolymer precursor technique. Micron‐level pores with a homogeneous pore‐size distribution were introduced into the inorganic framework using foaming agents. The results demonstrated that the apparent density, pore‐size distribution and specific surface area of porous geopolymer precursors can be well‐engineered via tailoring the category and concentration of the foaming agent. After being treated at 900°C, hexagonal SrAl 2 Si 2 O 8 first‐crystallized from the amorphous geopolymer matrix and then gradually converted into monoclinic SrAl 2 Si 2 O 8 between 1100°C and 1200°C. The resulting monoclinic SrAl 2 Si 2 O 8 ceramics maintained the porous structures during high‐temperature treatments and exhibited high porosity, specific surface area, and compressive strength. The aforementioned strategy not only achieves monoclinic SrAl 2 Si 2 O 8 ceramics with well‐defined and robust microstructures, but also provides an alternative route to prepare other porous ceramics, with potential applications in fields of high‐temperature filters, adsorbents, and heterogeneous catalysis.