摘要
测定了25℃时硅胶自单组分水溶液及二元混合水溶液中吸附溴化十六烷基三甲铵(CTAB)、溴化十四烷基三甲铵(TTAB)和溴化十四烷基吡啶(TPB)三种阳离子表面活性剂的等温线。结果表明,(1)自单组分溶液和混合溶液中的吸附等温线均为两平台型;(2)混合体系中,各组分的分吸附量在低平衡浓度和高平衡浓度时比其单独存在时的小,而在中等浓度区域时却有增加;(3)混合体系中总吸附等温线分于组成此体系的,两组分单独存在时的等温线之间,且更靠近表面活性较高组分的等温线。说明混合体系中的吸附性质主要取决于表面活性高的组分。文中对所得的结果进行了解释。按照半胶团浓度(HMC)时每个吸附分子都是独立的吸附中心的假设计算了各体系的半胶团最小聚集数,其值在6～11范围。
The adsorption isotherms of cetyltrimethylammonium bromide (CTAB), tetradecyl-trimethylammonium bromide (TTAB) and tetradecylpyridinium bromide (TPB) from their single and binary mixed aqueous solutions en silica gel at 25℃ have been determined. The results show that (1) the isotherms from single and mixed solutions are all characterized by two plateaux; (2) in the mixed systems, the adsorption amount of each component is decreased at low and high concentration range, but increased at medium concentration range; (3) the isotherms of total adsorption amount vs. total concentration in the mixed systems lie between those of the pure components of which the systems consist, but more close to those of the components haying higher surface activity. It is suggested that the adsorption properties in the mixed systems are determined dominantly by the higher surface active components. The minimum aggregation number of the hemimicelle, calculated according to the assumption that each adsorbed surfactant molecule is an independent adsorption centre at hemimicelle concentration (HMC), is in the range of 6-11.
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1989年第2期146-152,共7页
Acta Scientiarum Naturalium Universitatis Pekinensis
关键词
硅胶
阳离子
表面活性剂
吸附
Mixed adsorption
Cationic surfactant
Silica gel
Hemimicelle
Aggregation number
