Solutions of sodium dodecyl benzene sulfonate (SDBS) and N , N -dimethyldodecan-1-amine oxide (DDAO) with mole fractions of 0.00, 0.25, 0.50, 0.75 and 1.00 were prepared and their surface tension was measured as a function of total surfactant concentration. The critical micelle concentration (CMC) values of these mixed solutions were also determined. The minimum area occupied by a surfactant molecule at air/water interface was calculated for single and binary surfactant mixtures. A pronounced synergistic interaction between SDBS and DDAO was detected. The surface tension and CMC-values of SDBS/DDAO mixtures are significantly lower than those of the single surfactant. The mixed system of SDBS/DDAO exhibits a highly negative interaction parameter ( β = −10.6) according to regular solution model, and is found to fulfill the condition of Hua and Rosen, indicting a strong synergistic interaction between the two surfactants. The contact angle measurements show the wettability of the surfactant mixture onto polyethylene substrate is higher than of the respective single surfactant. In addition, the adsorption of SDBS and DDAO or their mixtures on 1.0% activated carbon and 5.0% Jordanian natural clay (JNC), respectively, was investigated using the depletion method. The individual surfactants were found to adsorb to a considerable extent on activated carbon, and a slightly higher adsorption tendency was even measured for mixed SDBS/DDAO surfactant systems. Although no SDBS molecules adsorbed on JNC, adsorption was observed for solutions containing DDAO and SDBS/DDAO surfactants. The improvement in wettability and adsorption of SDBS/DDAO surfactants at the air/water and solid/water interfaces is directly related to the synergistic interaction between the two surfactants.

中文翻译：

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十二烷基苯磺酸钠 (SDBS) 与 N,N-二甲基十二烷-1-氧化胺 (DDAO) 的协同作用及其在活性炭和约旦天然粘土上的吸附

制备摩尔分数为 0.00、0.25、0.50、0.75 和 1.00 的十二烷基苯磺酸钠 (SDBS) 和 N, N-二甲基十二烷-1-氧化胺 (DDAO) 溶液，并测量其表面张力与总表面活性剂的函数关系浓度。还确定了这些混合溶液的临界胶束浓度 (CMC) 值。计算单一和二元表面活性剂混合物的表面活性剂分子在空气/水界面占据的最小面积。检测到 SDBS 和 DDAO 之间存在明显的协同作用。SDBS/DDAO混合物的表面张力和CMC值明显低于单一表面活性剂。根据正则解模型，SDBS/DDAO的混合系统表现出高度负的相互作用参数（β=-10.6），满足Hua和Rosen的条件，表明两种表面活性剂之间有很强的协同作用。接触角测量显示表面活性剂混合物在聚乙烯基材上的润湿性高于相应的单一表面活性剂。此外，分别使用耗尽法研究了 SDBS 和 DDAO 或其混合物在 1.0% 活性炭和 5.0% 约旦天然粘土 (JNC) 上的吸附。发现单个表面活性剂在相当程度上吸附在活性炭上，甚至测量到混合 SDBS/DDAO 表面活性剂体系的吸附趋势略高。虽然没有 SDBS 分子吸附在 JNC 上，但在含有 DDAO 和 SDBS/DDAO 表面活性剂的溶液中观察到吸附。