Hierarchical microstructure and formative mechanism of low-density molybdena-based aerogel derived from MoCl5

• Published in: Journal of sol-gel science and technology 2011-04, Vol.58 (1), p.225-231
• Main Authors: Du, Ai, Zhou, Bin, Zhong, Yanhong, Zhu, Xiurong, Gao, Guohua, Wu, Guangming, Zhang, Zhihua, Shen, Jun
• Format: Article
• Language: English
• Subjects: Additives; Aerogels; Carbon dioxide; Ceramics; Chemical industry; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Crosslinking; Density; Derivatives; Exact sciences and technology; Fibers; Gelation; General and physical chemistry; Glass; Inorganic Chemistry; Materials Science; Microstructure; Molybdenum oxides; Morphology; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Polyacrylic acid; Porous materials; Propylene oxide; Sol-gel processes; Supercritical fluids
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-010-2381-8

Low density 150 kg/m 3 molybdena-based aerogel was prepared by using MoCl 5 as precursor, polyacrylic acid (PAA) as additive and propylene oxide as gelation accelerator via the dispersed inorganic sol–gel method, followed by carbon dioxide supercritical fluid drying. Characterizations of the composition indicate that the as-synthesized aerogel is composed of molybdenum oxide and PAA derivatives; electron microscopy photographs show the hierarchical microstructure of the aerogel, including both spherical secondary particles and root-like primary fibers. Based on the analysis of coordination state and special morphology, it is suggested that the additive PAA not only guides the growth of the primary fibers but improves the crosslinkage between the secondary particles to form a robust skeleton.