NaCl对烷基苯磺酸盐Gemini表面活性剂水溶液性质的影响  

Effect of NaCl on the Properties of Alkylbenzene Sulfonate Gemini Surfactant

作　　者：孟君[1] 路遥[1] 吴会觉[1] 张鑫[1] 

机构地区：[1]中国科学院理化技术研究所,北京100190

出　　处：《化学通报》2009年第10期942-945,共4页Chemistry

摘　　要：采用旋滴法测定了烷基苯磺酸盐Gemini表面活性剂Ia水溶液与正庚烷的界面张力,用超微电极循环伏安法测定了水溶液中Ia的胶束扩散系数。结果发现,NaCl的加入能够使界面张力降低2倍左右,使Ia的胶束扩散系数变大;Ia浓度增大,胶束扩散系数变小,而NaCl浓度增大,胶束扩散系数变大。这些变化说明NaCl的加入使得Ia胶束大小发生了变化。这是由于NaCl的加入降低了Ia离子头基之间的静电斥力,使得Ia分子排列更加紧密,更有效降低了油水的界面张力,使胶束形状变小;同时胶束表面电荷得到中和,胶束的静电斥力相应减小,胶束流动性相应增加,从而表现出较大的胶束扩散系数。spinning drop method and ultramicroelectrode （UME） cyclic voltammetry. Spinning drop method and UME are used to measure the interfacial tension between Gemini Ia aqueous solution and heptane and the diffusion coefficient of Ia in aqueous solutions. It has been found that the interfacial tension decreases and the diffusion coefficient increases with the addition of Nacl; the diffusion coefficient decreases with the increase of concentration of Ia and increases with the increase of concentration of NaCl, which indicates that NaCl has influence on the size of la micelles. All the results showed that NaCl affects the properties of alkylbenzene sulfonate Gemini surfactant Ia, this is because that electrostatic force reduces the electrostatic repulsion forces between ionic groups of Ia, which leads to a tighter arrangement of la and then reduces the interfacial tension and diminishes the size of micelles; mieelles surface charge has been neutralized, so the electrostatic repulsion force between micelles decreases and the mobility of the micelles increases, which shows a larger diffusion coefficient.

关 键 词：烷基磺酸盐Gemini表面活性剂 胶束扩散系数 界面张力 

分 类 号：O647.2[理学—物理化学] TQ464.8[理学—化学]