Formation of Particles in Sol-Gel Process
| Autor: | Sumio Sakka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | KONA Powder and Particle Journal, Vol 7, Iss 0, Pp 106-118 (2014) |
| Druh dokumentu: | article |
| ISSN: | 0288-4534 2187-5537 |
| DOI: | 10.14356/kona.1989017 |
| Popis: | The formation of particles in starting solutions and its significance for the sol-gel processing of oxide materials are reviewed on the basis of previous works including our work. First, hydrolysis and polycondensation reactions of metal alkoxides in alcohol-water solutions are briefly discussed. Then, it is shown that powders prepared by the sol-gel method using metal alkoxides are suitable as starting powders for high performance glasses and ceramics because the particles produced are fine, monodispersed and uniform in chemical composition. It is also shown that the formation of round-shaped particles larger than, say, 10 nm in sols may lead to porous silica monoliths of plate or rod shape without occurrence of cracks during drying of the wet gel. It should be noted that crack-free gel monoliths can be sintered to monoliths of glass and ceramics. It is shown that essentially one-dimensional long-shaped particles can be produced by adjusting the composition and conditions of processing of the starting solution, which is required for fiber drawing from viscous sols in the course of sol-to-gel conversion. |
| Databáze: | Directory of Open Access Journals |
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