### 全氟辛酸钠和溴化烷基三甲铵混合水溶液的界面化学性质

1. 北京大学物理化学研究所
• 收稿日期:1987-05-18 修回日期:1988-02-24 发布日期:1988-12-15
• 通讯作者: 丁慧君

### INTERFACE CHEMICAL PROPERTIES OF THE MIXED AQUEOUS SOLUTION OF SODIUM PERFLUOROOCTANOATE AND ALKYLTRIMETHYLAMMONIUM BROMIDE

Ding Huijun; Chen Shaomo; Wang Lu; Zhao Guoxi

1. Laboratory of Colloid Chemistry; Institute of Physical Chemistry; Peking University
• Received:1987-05-18 Revised:1988-02-24 Published:1988-12-15
• Contact: Ding Huijun

Abstract: The interface adsorption and micelle formation of the mixed solution of fluorocarbon and hydrocarbon surfactants (7CFNa and C_8NBr, C_(10)NBr, C_(12)NBr mixtures) have been investigated. The surface tension and interfacial tension of the mixed solution have been determined by the drop-volume method (the ionic strengths of the solution are kept constant in 0.1 mol~(-1)L by adding NaBr).
By applying the Gibbs adsorption equation and using nonideal solution theory, the total adsorption amount and the individual adsorption amounts of each surfactant have been obtaioned. It has been shown that (I) at the surface the adsorption rules of various systems are essentially the same. At the heptane/water interface, the adsordtion rule of 7CFNa-C_3NBr system is similar to that at the surface, for 7CFNa-C_(10)NBr mixture the amount of satuated adsorption increases with increase in the molar ratio of any one surfactant from the 1:1 ratio at which the saturated adsorption amount is the least. However, the saturated adsorption amount for 7CFNa-C_(12)NBr system decreases with decrease in the mole ratio of 7CFNa in the mixture the adsorption rule is contrary to that at the surface; (2) The surfactant mixture has a very high interfacial activity. The efficiency of surface tension decreases and the effectiveness of surface tension increases with the increase in hydrocarbon chain length in cationic surfactants.