The effect of some added electrolytes, viz. NaCl, CaCl₂ and AlCl₃, on the critical micelle concentration (CMC), maximum surface excess concentration (G_max) and minimum area per molecule (A_min) at air-liquid interface of a cationic surfactant cetylpyridinium chloride (CPC) in aqueous solutions have been studied at 288.15, 293.15 and 298.15 K using tensiometric method. The effect of an added electrolyte on decreasing CMC of CPC is found to be in the order (AlCl₃) > (CaCl₂) > (NaCl), which falls in the same order as of the moles chloride ions furnished by each mole of the added electrolyte. The G_max decreases with increasing temperature and electrolyte concentration leading to an enhanced available area per molecule at the air-liquid interface. The process of micellization and adsorption of CPC at air-liquid interface are both favoured by exothermic enthalpy change as well as entropy gain. The observed features such as lowering of CMC, higher thermodynamic micellar stability, more relaxed surfactant molecules at the interface, due to an added electrolyte, may be exploited for improving the efficiency of the surfactant as a detergent, solubilizing agent, froth floatation process for concentrating ores, petroleum oil recovery and oil spill management.

中文翻译：

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某些添加电解质对十六烷基氯化吡啶在水介质中的表面和热力学性质的影响

一些添加的电解质的影响，即。水溶液中阳离子表面活性剂十六烷基吡啶鎓氯化镉（CPC）的临界胶束浓度（CMC），最大表面过量浓度（G _max）和每分子最小面积（A _min）的NaCl，CaCl ₂和AlCl ₃已经使用张力测定法在288.15、293.15和298.15 K上研究了溶液。发现添加电解质对降低CPC的CMC的影响依次为（AlCl ₃）>（CaCl ₂）>（NaCl），其顺序与每摩尔CCl所提供的氯离子摩尔数相同。添加电解质。_最大G随温度和电解质浓度的增加而降低，从而导致气-液界面上每个分子的可用面积增加。放热焓变和熵增均有利于CPC在气液界面处的胶束化和吸附过程。所观察到的特征，例如降低的CMC，更高的热力学胶束稳定性，由于添加了电解质而在界面处更松弛的表面活性剂分子，可用于提高表面活性剂作为洗涤剂，增溶剂，泡沫浮选浓缩的效率。矿石，石油采收和漏油管理。