Studies on Powdered Preparations. XV. Aging of Dried Aluminum Hydroxide Gel under Humidity and in Water

概要

論文の詳細を見る
Commercial DAHG J.P. (G-A and G-B) were kept in various atmosphere under relative humidity and in distilled water at 30° and the following results were obtained. 1. BET specific surface area by the adsorption of water was a little larger than that by the adsorption of nitrogen and the difference between both values of G-B, which had less specific surface area and inferior anti-aging properties, was larger. 2. When both samples were kept standing under high humidity or in water, at an early stage of the aging process, their neutralizing rates became faster temporarily. This phenomenon was observed remarkably with G-B. 3. The sample aged under high humidity with the lapse of time were considered to change in the following process : Amorphous→boehmite-like substance→bayerite + gibbsite ; i.e., finally transferred to a mixture of bayerite and gibbsite. 4. Infrared absorption spectra of the aged samples, which lost the neutralizing reactivity, showed their characteristic absorption band around 1020〜960 cm^<-1>.
1966-02-25