【摘要】 利用Langmuir膜天平测定不对称双子表面活性剂12-2-16和对称双子表面活性剂12-2-12在空气-水界面上形成单分子膜的表面压,通过单分子膜的π-A等温线、微分等温线和静态弹性,分析其相转变和成膜特性.结果表明,与传统阳离子表面活性剂DTAB比较,12-2-16、12-2-12比DTAB单分子膜的分子极限面积大,崩溃压高,并有较高的静态弹性,因而具有较高的凝聚性和稳定性,其中12-2-16单分子膜的凝聚性和稳定性最高.更多还原

【Abstract】 Monolayers of a dissymmetric cationic quaternary ammonium gemini surfactant 12-2-16 and a symmetric gemini surfactant 12-2-12 were formed in KSV 2000 Langmuir trough at air-water interface,respectively.The surface pressure of each monolayer was measured using the Wilhelmy plate technique.The features of monolayers at air-water interface were discussed by analyzing the π-A isotherm,the differential curve and the static surface elasticity of monolayers for 12-2-12 and 12-2-16.It was found that such parameters as the molecular limited area,the collapse surface pressure,the static surface elasticities are higher for 12-2-12 and 12-2-16,in comparison with those of a conventional cationic surfactant,dodecyl-trimethylammonium bromide(DTAB).Among the surfactants studied,12-2-16 monolayer has the highest cohesion and stability.更多还原