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化学学报
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化学学报 ›› 2004, Vol. 62 ›› Issue (16): 1491-1494. 上一篇    下一篇

研究论文

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

PDF

649

被引次数

88

一般认为无机盐对等链长正负离子表面活性剂等摩尔混合体系的表面活性没有明显影响.通过测定等摩尔癸基三乙基溴化铵和癸烷磺酸钠混合体系在卤化钠(NaX,X=F-,Cl-,Br-,I-)溶液中的表面活性,发现高浓度的无机盐具有明显影响,使混合表面活性剂的临界胶束浓度(cmc)降低,水溶液的最低表面张力(γcmc)升高.无机盐的影响程度随NaX中X的离子半径增加而增大.可通过无机反离子对正负离子表面活性剂头基之间吸引作用的"屏蔽"及"盐析"作用对结果加以解释.

关键词: 表面活性剂, 正负离子表面活性剂混合体系, 表面张力, 表面活性

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