亲水性硅胶选择吸附次序的一种解释

亲水性硅胶选择吸附次序的一种解释 AN EXPLANATION OF ADSORPTION ORDER FOR SILICA GEL 李培森 Li Peisen Gu Tiren 1 first-author 顾惕人 1 北京大学化学系 北京大学化学系 在20℃测定了硅胶在五个理想二元溶液全组分范围内的吸附。这五个理想溶液是苯—甲苯、苯—氯苯、甲苯—氯苯,甲苯—溴苯及氯苯—溴苯,得到吸附顺序如下: 苯>甲苯>氯苯>溴苯发现单从吸附物的某种分子特性的观点难于解释上列吸附顺序,在对实验和文献数据以及硅胶亲水特性作了分析之后,基于吸附物在水中的溶度顺序提出了一种定性解释,它与对水相和对硅胶表面的界面张力顺序是相合的。因此,硅胶从五个二元理想溶液中的吸附行为与Gibbs吸附理论所预示的是一致的。 The adsorption from five perfect binary liquid mixtures on silica gel at 20℃ has been determined in the whole composition range. The five mixtures studied are benzene-toluene, benzene-chlorobenzene, toluene-chlorobenzene, toluene-bromobenzene and chlorobenzene-bromobenzene, the adsorption order obtained is as follows. benzene>toluene>chlorobenzene>bromobenzene It has been found difficult to explain the above adsorption order from the point of view of some aspect of the molecular character of the adsortbate alone. After analysis of both the experimental and literature data, of the silica gel hydrophilic charaeter, a qualitative explanation is given based on the solubility order of the adsorbates in water, which is in harmony with the interfacial tension order to water phase and to silica gel surface. Therefore, the adsorption behavior from the five perfect binary liquid mixtures on silica gel is in agreeemnt with the prediction of the Gibbs’ adsorption theory. 1980-04-01 2021-04-01 4