论文部分内容阅读
使用最大气泡法测定了十八烷基二甲基氯化铵 (C18DAC)水溶液的动态表面张力 ,考察了浓度、温度等对其DST的影响 ,详细表征了DST随时间的变化过程 ,计算了动态表面张力的各种参数 (n ,ti,t ,tm,R1/ 2 ) .结合Word Tordai方程计算了表观扩散系数 (Da)和吸附势垒 (Ea) ,对其吸附动力学模式进行了研究 ,探讨了DST参数的物理意义 .结果表明 ,t 值越小 ,吸附势垒Ea 越大 ,宏观扩散系数Da 越小 ,表面活性剂分子越不易吸附在溶液表面 ;C18DAC低浓度时吸附属于扩散控制模式 ,高浓度时属于混合控制模式 ;高浓度时 ,在吸附初期 (t→ 0 )为扩散控制模式 ,吸附后期 (t→∞ )为混合控制模式 .
The dynamic surface tension of octadecyldimethylammonium chloride (C18DAC) aqueous solution was determined by the maximum bubble method. The influence of concentration and temperature on its DST was investigated. The variation of DST with time was characterized in detail. (N, ti, t, tm, R1 / 2) of surface tension were calculated.The apparent diffusion coefficient (Da) and adsorption barrier (Ea) were calculated by the Word Tordai equation and the adsorption kinetics model was studied , The physical meaning of DST parameters was discussed.The results showed that the smaller the value of t is, the larger the adsorption barrier Ea is, and the smaller the macroscopic diffusion coefficient Da is, the more difficult the surfactant molecules are to adsorb on the surface of the solution. (T → 0) for the diffusion control mode at the high concentration and the hybrid control mode for the latter stage (t → ∞) at the high concentration.