Acta Chimica Sinica ›› 2004, Vol. 62 ›› Issue (16): 1491-1494. Previous Articles     Next Articles

高浓度无机盐对正负离子等摩尔混合表面活性剂表面活性的影响

张莹, 陈莉, 肖进新, 马季铭   

  1. 北京大学化学与分子工程学院, 北京, 100871
  • 投稿日期:2003-12-11 修回日期:2004-04-20 发布日期:2014-02-17
  • 通讯作者: xiaojx@chem.pku.edu.cn
  • 作者简介:肖进新:E-mail:xiaojx@chem.pku.edu.cn;Tel:010-62764973.
  • 基金资助:
    国家自然科学基金(Nos.29973002,20273006)资助项目.

Effect of Salt with High Concentration on Surface Activities of Equimolar Mixtures of Cationic-Anionic Surfactants

ZHANG Ying, CHEN Li, XIAO Jin-Xin, MA Ji-Ming   

  1. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871
  • Received:2003-12-11 Revised:2004-04-20 Published:2014-02-17

It is usually thought that inorganic salts have little effect on the surface activity of equimolarly mixed cationic-anionic surfactant mixtures.This work studied the effect of sodium halide (NaX, X=F-, Cl-, Br-, I-) on the surface activity of equimolarly mixed decyltriethylammonium bromide-sodium decanesufonate.It was showed that the added salts with high concentration had obvious effect on the surface activities, and the critical micelle concentration (cmc) was decreased, while the lowest surface tension of the aqueous solution (γcmc) was increased.Such effects were increased with ion radius of X- of NaX.The results were explained in terms of the “screening” effect of inorganic counter ions on the attraction between oppositely charged headgroups of mixed cationic-anionic surfactants and the “salt out” effect.

Key words: surfactant, cationic2anionic surfactant mixture, surface tension, surface activity