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近年来,胶束增溶吸光光度法,浊点析相法及泡沫浮选法在化学分析中的应用日趋增加。在这些体系中,皆需加入适量的界面活性剂。而临界胶束浓度(CMC)又是界面活性剂及其溶液性质的重要参数,因此分析工作者需一测定界面活性剂溶液CMC的准确而又简便的方法。本文提出的毛细管中液面上升高度法,不需要特殊的仪器设备,操作简便,准确度可满足日常工作的要求。界面活性剂与CMC 界面活性剂是一类有亲水基团的长链有机化合物,如澳化十六烷基三甲基铵(CTMAB),十二烷基苯磺酸钠(SDBS),聚氧乙烯失水山梨醇单油酸酯(Tween 80)等。根据任何体系的自由能总有自动减小倾向的原理,若将少量的界面活性剂加入水中,其分子结构中的亲水基团便埋在水面下,疏水基则因被水分子排斥而翘出液面,即自由能小的疏水基取代了自由能大的水分子而排列在溶液界面上(图1a)。这种
In recent years, the application of micellar solubilization spectrophotometry, cloud point phase analysis method and froth flotation method in chemical analysis is increasing. In these systems, all need to add the right amount of surfactant. The critical micelle concentration (CMC), in turn, is an important parameter for surfactant and its solution properties, so analysts need an accurate and easy way to determine the surfactant solution CMC. In this paper, the capillary rise in liquid height method, does not require special equipment, easy to operate, accuracy to meet the daily work requirements. Surfactants and CMC surfactants are a class of long chain organic compounds with hydrophilic groups such as CTMAB, SDBS, Oxyethylene sorbitan monooleate (Tween 80) and the like. According to any system of free energy there is always the principle of automatic reduction of tendency, if a small amount of surfactant is added to water, the molecular structure of hydrophilic groups buried in the water surface, hydrophobic due to water molecules excluded due to Alice The liquid surface, that is, the small free-energy hydrophobic group, displaces the large free-energy water molecules and is arranged at the solution interface (Figure 1a). This