协同效应对复配体系表面化学性能及聚集体的影响

Effects of synergy on the surface activities and aggregates of surfactant mixtures

将N-月桂酰基谷氨酸钠(SLG)分别与十二烷基三甲基氯化铵(DTAC)和十二烷基甜菜碱(BS-12)以不同比例混合,研究不同类型表面活性剂之间的相互作用对表面化学性能和形成胶束的影响。通过规则溶液理论研究了不同摩尔比的复配体系的表面化学性质,使用激光光散射表征复配体系的胶束分布和平均流体力学半径,使用荧光探针法测量复配体系的微极性和胶束聚集数。结果表明,两个复配体系均表现出全面增效的协同作用,均在SLG摩尔分数x=50%时表现出最佳协同效应,并且阴离子表面活性剂与阳离子表面活性剂之间具有更强的作用力。SLG/DTAC复配体系在10倍cmc下趋向于产生单一稳定且小于单一组分的聚集体,SLG/BS-12复配体系在10倍cmc下形成棒状胶束,胶束大小分布较宽。

The mixture of sodium N-lauroyl glutamate(SLG)and dodecyltrimethylammonium chloride(DTAC)and the mixture of SLG and dodecyl betaine(BS-12)in different ratios were studied to investigate the effects of the interactions between different types of surfactants on surface chemical properties and micelle formation.The surface chemical properties of the mixed systems with different molar ratios were investigated by regular solution theory.Laser light scattering was used to characterize the micelle distribution and average hydrodynamic radius of the mixed systems.Fluorescence probing method was used to measure micropolarity and micellar aggregation number.The results indicated that both the mixed systems showed synergy of overall enhancement.The two systems showed the best synergy when x(SLG)=50%,and the interaction between anionic and cationic surfactants was stronger.The SLG/DTAC system tended to produce single stable aggregates at a concentration of ten times cmc,but the size after mixing was smaller than that of single components.The SLG/BS-12 system formed rod-shaped micelles at a concentration of ten times cmc,and the micelle size distribution was wide.