关键词: 表面活性剂, 四氯化碳, 聚集体, 脂肪酸 P, 增溶, 反胶束, 聚集行为, 十二烷基铵, 碘光谱法

The Aggregation of dodecylammonium acetate (DAA), dodecylammonium propionate (DAP) and dodecylammonium Butyrate (DAB) have been investigated by spectrometric iodine method and water solubilization, the (cmc)~I~S determined by spectrometric iodine method are 2.0×10^-^4, 2.2×10^-^4 and 4.3×10^-^4mol·dm^-^3, respectively, and the (cmc)~W~S by water solubilization are 2.0×10^-^3, 3.5×10^-^3 and 10.5×10^-^3mol·dm^-^3, respectively. The (cmc)~I~S are lower by one order of magnitude than the corresponding (cmc)~W~S. The reason is probably that the aggregates with low aggregation number start to form at (cmc)~I, which are not capable to solubilize water. Water solubilization starts only when the aggregation number of reverse micelles is high enough, which occur at (cmc)~W, the concentration is much higher than (cmc)~I. The experiment shows that the reverse micelles of DAA, DAP and DAB are able to solubilize up to respective 4.3, 9.4, and 13.5 molecules of water per surfactant molecule respectively. According to simplified spherical reverse micelle model, the aggregation numbers of DAA, DAP and DAB reverse micelles which solubilize limiting amount of water are 24, 122 and 252, the radii of water pool are 0.90, 2.02 and 2.90nm, and radii of free water pool are 0.33, 1.68 and 2.58nm, respectively.

Key words: SURFACTANTS, CARBON TETRACHLORIDE, AGGREGALES, FATTY ACID P, SOLUBILIZATION