本文用电导法在313.2K、318.2K、323.2K和328.2K下,测定了正十二烷基磺酸钠(简记为AS)的临界胶束浓度(CMC)和胶束解离度。我们考虑了解离度同温度的关系,从而对离子型表面活性剂计算胶束形成焓(△H_m~0)的现有公式作些改进。与此同时,也计算了313.2K下AS在水溶液中的△H_m~0值。在RD-I型热导式自动量热计上,按稀释法。对该值作了量热测定。结果表明,修正后的△H_m~0计算式,其准确性有所提高。 In this paper, the critical micelle concentration (CMC) and micellar dissociation degree of sodium n-dodecyl sulfonate (abbreviated as AS) were measured at 313.2K, 318.2K, 323.2K and 328.2K by conductivity method. We consider the dependence of dissociation temperature on the temperature and thus make some improvements to the existing formula for calculating the enthalpy of formation of micelle (ΔH_m ~ 0) for ionic surfactants. At the same time, △ H_m ~ 0 value of AS in aqueous solution was also calculated at 313.2K. RD-I type of thermal conductivity in the automatic calorimeter, according to the dilution method. The value of calorimetry was measured. The results show that the accuracy of the modified ΔH_m ~ 0 formula is improved.