抄録
The adsorption of alcohol molecules on silica gel was investigated in a wide range of the alcohol concentrations in a water solution. Adsorption isotherms of ethanol and 1-propanol from the aqueous solutions were measured and analyzed in terms of the surface excess amount of adsorption. The composite adsorption isotherms were well expressed by a Dubinin-Radushkevich type equation. The individual isotherm, which was calculated by assuming a simple volume-filling model, showed that the pores of the silica were filled with the alcohol at a mole fraction higher than about 0.8.
The surface hydroxyl groups of silica gel were partially alkoxylated to the alkoxyl groups even in contact with the alcohol in the presence of water. The number of formed alkoxyl groups increased with increase in the concentration of the alcohol in the solution. The equilibrium constant for the alkoxylation reaction was calculated.
