硅烷化活性炭的吸附性质

本工作测定了25℃和35℃时硅烷化活性炭自水溶液中吸附苯甲酸和苯甲醛的等温线;计算了吸附过程的ΔGⅲ,ΔHⅲ和ΔSⅲ;用Hill-deBoer方程处理了实验结果。所得结果表明:(1)随硅烷化时间延长,苯甲酸和苯甲醛的吸附量(mol.m^-^2)明显增加;-ΔGⅲ和-ΔHⅲ略有升高,ΔSⅲ为正值;(2)吸附分子之间的相互作用很弱,吸附分子与活性炭表面间的作用随硅烷化程度增加而加大;(3)芳香化合物可能是以苯环吸附在炭表面上的。

The adsorption properties of the silanized active carbon

The adsorption isotherms of benzoic acid and benzaldehyde from aqueous solution onto the silanized active carbon have been measured at 25℃ and 35℃. The changes of standard free energy ΔGⅲ, enthalpy ΔHⅲ and entropy ΔSⅲ in adsorption processes have been calculated from the Langmuir parameter. The experimental data have been treated with Hillde Boer equation. The results show that, (1)with the lapse of the silanized time, the adsorption amounts (mol.m^-^2) of benzoic acid and benzaldehyde increase greatly; -ΔGⅲ, -ΔHⅲ increase slightly, and ΔSⅲ shows to be positive. (2)the interaction between adsorbed molecules is weak, and the interaction between adsorbed molecule and the surface of the active carbon increase with silanization. (3)the benzene ring of the benzoid compounds is adsorbed on the surface of the active carbon.