Irreversible Adsorption of Methanol Vapor on Silica Surface.
スポンサーリンク
概要
- 論文の詳細を見る
Irreversible adsorption of methanol vapor on sillica surface was studied through the measurements of adsorption isotherms and IR absorption as well as differential thermal analysis. Dependencies of irreversible methanol adsorption on the preheating temperature and the vapor pressure was investigated to evaluate the reactivity of silica surface.The irreversible adsorption occurs by two mechanisms, i. e., formation of hydrogen bond and surface methoxylation reaction which forms methoxy groups. DTA profiles of methoxy groups reflects the states of hydroxyl groups on the surface. Isolated methoxy groups exhibited DTA exothermic peaks at higher temperature. They were formed from the isolated hydroxyl groups on the surface preheated at temperatures above 400°C. The surface methoxylation reaction occurred mainly on the isolated hydroxyl groups at a low pressure, while methoxylation of siloxane bridges took place at a pressure higher than that of multilayer formation and was promoted by the methanol vapor condensation in the pores.
- 粉体工学会の論文