糖基双子阳离子表面活性剂的表面活性

摘要

Equilibrium surface tension and dynamic surface tension of four kinds of sugar - based Gemini cationic surfactant (SGCS )were determined with Wilhelmy method and maximum bubble pressure method;and the surface activity of SGCS was evaluated. Value of γcmc of SGCS is about 30 mN/m and cmc is in order of magnitude of 10 -4 mol/L,which is 1 -2 order of magnitude lower than that of conventional cationic surfactants. It showed that SGCS has excellent surface activity. There are linear relationship between lg ccmc and carbon number of the hydrophobic group,as well as pc20 and carbon number of the hydrophobic group. Following the increasing of concentration of SGCS and temperature,the decreasing rate of the dynamic surface tension rises rapidly. It showed that the higher the temperature,the stronger the dynamic surface activity of SGCS.%通过吊片法和最大泡压法测定了4种糖基双子阳离子表面活性剂（SGCS）的平衡表面张力和动态表面张力，对其表面活性进行了评价。SGCS的γcmc在30 mN／m左右，cmc均在10－4 mol／L数量级，比普通阳离子表面活性剂的cmc低1～2个数量级，表明SGCS具有优良的表面活性。SGCS的lg ccmc和pc20与疏水基的碳链长度符合线性关系。随着SGCS浓度的增大，动态表面张力下降速度加快，更容易达到介平衡。随着温度的升高，动态表面张力下降速率加快，说明温度越高动态表面活性越强。