媒体撹はん型ミルにおけるチタニアの超微粉砕同時表面処理による超微粒子化過程

Abstract

Ultra-fine grinding of titania accompanied by simultaneous surface treatment was conducted in a laboratory-scale media agitating mill. The grinding solvent was n-decane, and stearic acid was added to the solvent as the surfactant. Zirconia beads of 0.6mm diameter were used as the grinding media. The effect of grinding time on the characteristics of titania commimuted in the media agitating mill was investigated. The measured characteristics were true density, specific surface area, particle size distribution, crystallite size, crystal lattice distortion and morphology of the comminuted titania. The amount of contamination of the comminuted titania from the grinding media, rotator and mill wall was also measured.Titania became flaky by surface attrition during the initial stage of grinding. Subsequently, the flaky particles were ground into ultra-fine particles. The comminuted titania had low crystal lattice distortion in the order of 10-4 and a small crystallite size of less than 200A after 5 hours of grinding. The true density of the comminuted titania was almost the same as that of intact titania. There was almost no increase in the background intensity in the XRD profile, and the lattice constant of the comminuted titania was kept constant.