十五烷基芳基磺酸钠溶液表面性质的影响因素研究

测定了自制的四种高纯度十五烷基间二甲苯磺酸钠在纯水溶液和0.0393 mol/L异丙醇溶液中的表面性质，结果表明，随芳基向碳链中间位置的移动，临界胶束浓度cmc增大，分子极限占有面积Amin增大，标准吸附自由能 变得更负，降低表面张力的效率pc20增强，饱和吸附量Γ_max降低，临界胶束浓度时的表面张力γ_cmc降低；且异丙醇的加入使磺酸钠溶液的临界胶束浓度显著降低。从分子结构的特点探讨了分子支化程度对表面性能的影响。

Study on the Effecting Factors of Surface Properties of pentadecyl m-xylene sodium sulfonates Solution

The surface properties of pentadecyl m-xylene sodium sulfonates synthesized by our laboratory in pure water and 0.0393mol?L-1 isopropanol solution were measured. The measurements indicated that the critical micelle concentration (cmc) , the saturated adsorption area Amin and the negative logarithms of surfactant concentration needed in order to reduce surface tension 20 mN/m (pc20) increased, the standard free energy of adsorption( ) became more negative, the surface tension at the cmc (γcmc) and maximum surface excess at the cmc(Γmax) decreased with the moving of the aryl from the terminal to the center of the long alkyl chain. And with the addition of isopropanol the cmc decreased. The effect of molecular branched structure on surface properties were explained from the view of molecular structure.