The interaction of an anionic textile dye, acid red 151 (AR), with a cationic surfactant, cetyltrimethylammonium bromide (CTAB), in aqueous electrolyte medium (e.g., KCl, NaCl) and in H₂O + ethanol medium was observed using the conductometric method. Two critical micelle concentrations (CMC) were found for the AR + CTAB system in water and H₂O + ethanol medium, but only one CMC was detected for AR + CTAB in salt+H₂O media and for pure CTAB in all solutions. The change in CMC behavior of CTAB in the presence of AR indicates the occurrence of strong interaction between AR and CTAB. The extent of solubility increases with an increase of temperature, which disfavors micellization. The CMC values in NaCl solution are comparatively lower than those found in KCl solution, which signifies that the micelle formation is more favorable in attendance of NaCl. In aqueous ethanol solution, two CMC values were also observed for AR + CTAB that are higher than those obtained in water. The free energy of micellization () was negative, which illustrates a thermodynamically spontaneous micellization process. The values of enthalpy () and entropy () of micellization show that the process was entirely entropically driven at a lower temperature; but, enthalpic events are favored at elevated temperature in electrolyte medium, whereas both enthalpy and entropy are reduced in attendance of ethanol. In aqueous medium, the thermodynamic parameters signify the presence of electrostatic interaction between AR and CTAB at higher temperatures, while the hydrophobic interaction is the main driving force at a lower temperature. A linear expression of as a function of demonstrates enthalpy‐entropy compensation over the experimental conditions employed in this study.

中文翻译：

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添加剂和温度对酸性红151染料与十六烷基三甲基溴化铵相互作用的影响：电导法研究

使用电导法观察了阴离子纺织染料酸性红151（AR）与阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）在水性电解质介质（例如KCl，NaCl）和H ₂ O +乙醇介质中的相互作用。方法。在水和H ₂ O +乙醇介质中，AR + CTAB系统的两个临界胶束浓度（CMC）被发现，但在盐+ H ₂ O介质中，AR + CTAB和纯CTAB中仅检测到一个CMC。存在AR的情况下CTAB的CMC行为发生变化，表明AR与CTAB之间存在强相互作用。溶解度随温度的升高而增加，不利于胶束化。的NaCl溶液中的CMC值相对低于KCl溶液中的CMC值，这表明胶束形成对NaCl的参与更有利。在乙醇水溶液中，AR + CTAB的两个CMC值也比在水中获得的高。胶束化的自由能（）为负，说明了热力学自发胶束化过程。焓值（）和熵值（）的胶束化过程表明，该过程在较低的温度下完全由熵驱动；但是，在电解质介质中温度升高时，焓事件是有利的，而乙醇的参与会降低焓和熵。在水性介质中，热力学参数表示在较高温度下AR和CTAB之间存在静电相互作用，而在较低温度下疏水相互作用是主要驱动力。作为的函数的线性表达式证明了在这项研究中使用的实验条件下的焓-熵补偿。