Preparation of γ-alumina large grain particles with large specific surface area via polyol synthesis

• Published in: Ceramics international Vol. 41; no. 3; pp. 3631 - 3638
• Main Authors: Itoh, Toshio, Uchida, Toshio, Matsubara, Ichiro, Izu, Noriya, Shin, Woosuck, Miyazaki, Hiroshi, Tanjo, Hiromasa, Kanda, Keisen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2015
• Subjects: Aluminium; Aluminum; Aluminum oxide; Ceramics; Gamma-alumina; Molecular weight; Poly(vinylpyrrolidone) (PVP); Polyol synthesis; Polyols; Secondary particle size; Specific surface; Specific surface area; Synthesis; Secondary particle size; Polyol synthesis; Gamma-alumina; Specific surface area; Poly(vinylpyrrolidone) (PVP)
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2014.11.028

We developed the polyol synthesis of γ-alumina particles that allows for control of their particle size from the nanometer level to the micrometer level. The developed polyol synthesis utilized a reflux reaction of ethylene glycol solution with aluminum nitrate hexahydrate and poly(vinylpyrrolidone) (PVP). Two important process parameters – the molecular weight of PVP and refluxing temperature – were investigated to control the size of the alumina particles. Further, two growth models for amorphous alumina particles in polyol synthesis were suggested. γ-Alumina with secondary particle size ranging from 142nm to 1.0μm with a specific surface area ranging from 81 to 32m2/g was obtained. The α-alumina prepared by high-temperature annealing of over 1200°C had secondary particle sizes ranging from 246 to 330nm, but with specific surface areas of only 5.4–11m2/g. Therefore, it is proved that the polyol synthesis is able to control secondary particle size of γ-alumina upon maintaining a large specific surface area.