阴离子型表面活性剂溶液物理化学特征研究

Physical and Chemical Characteristics of Anionic Surfactants

贾奇锋 倪小明 李志恒

JIA Qifeng NI Xiaoming LI Zhiheng

为揭示温度对阴离子型表面活性剂在临界胶束浓度时的理化性质和胶束结构稳定性的影响规律，测定了十二烷基硫酸钠（C12H25SO4Na）和十二烷基苯磺酸钠（C18H29NaO3S）溶液的表面张力、泡沫半衰期和黏度等性能参数，研究了这两种表面活性剂溶液的黏度活化能、胶束化标准焓变和标准熵变等物理化学性质。结果表明，常温时，C12H25SO4Na和C18H29NaO3S 的临界胶束浓度分别为0.008 和0.002 mol/L。随着温度的升高，两种表面活性剂的表面张力和泡沫半衰期均呈指数型下降，黏度呈线型下降。C18H29NaO3S 的黏度活化能是C12H25SO4Na 的1.96倍，但C12H25SO4Na降低表面张力的效率和吸附趋势均大于C18H29NaO3S，其标准胶束化自由能和标准熵变均大于C18H29NaO3S，更容易产生胶束，且胶束结构更稳定。图12 表2 参15

In order to reveal the effect of temperature on the physical and chemical properties and the stability of micellar structure of anionic surfactant at critical micelle concentration，the surface tension，foam half-life and viscosity of sodium dodecyl sulfate （C12H25SO4Na） and sodium dodecyl benzene sulfonate （C18H29NaO3S） solution were measured. The physical and chemical properties such as viscosity activation energy，micelle standard enthalpy change and standard entropy change were studied. The results showed that the critical micelle concentration of C12H25SO4Na and C18H29NaO3S was 0.008 and 0.002 mol/L at room temperature respectively. The surface tension and foam half-life of two surfactants decreased exponentially and the viscosity decreased linearly with the increase of temperature. The viscosity activation energy of C18H29NaO3S was 1.96 times of that of C12H25SO4Na，but the efficiency of reducing surface tension and adsorption trend of C12H25SO4Na were more than that of C18H29NaO3S. The standard micellization free energy and standard enthalpy change of C12H25SO4Na were larger than that of C18H29NaO3S，and the micellar structure was more stable.

10.19346/j.cnki.1000-4092.2017.02.023