物理化学学报 >> 1995, Vol. 11 >> Issue (09): 785-790.doi: 10.3866/PKU.WHXB19950905

研究论文 上一篇    下一篇

十二烷基季铵盐及其与十二烷基硫酸钠混合体系的表面活性

赵国玺,肖进新   

  1. 北京大学化学系,北京 100871
  • 收稿日期:1994-09-29 修回日期:1994-11-30 发布日期:1995-09-15
  • 通讯作者: 赵国玺

Surface Activity of Dodecyltrialkylammonium Bromide and its Mixture with Sodium Dodecylsulfate

Zhao Guo-Xi,Xiao Jin-Xin   

  1. Department of Chemsitry,Peking University,Beijing 100871
  • Received:1994-09-29 Revised:1994-11-30 Published:1995-09-15
  • Contact: Zhao Guo-Xi

摘要:

通过表面张力测定,研究了十二烷基季铵盐C12H25N(CnH2n+1)3Br(n=1,2,3,4)及其与十二烷基硫酸钠混合体系的表面活性;应用规则溶液理论,计算了混合体系表面吸附层和胶团的组成及分子相互作用参数.对于季铵盐,极性基影响大:cmc随n增加而下降,γcmc则先上升(n=1-2),后下降(n=2-4).自极性基碳链的空间阻碍、疏水、弯曲效应,以及电荷屏蔽效应可对此予以解释.对于混合体系,极性基大小对其表面活性及胶团组成的影响较小.

关键词: 十二烷基三烷基溴化铵, 极性头效应, 正、负离子表面活性剂, 表面活性

Abstract:

The surface activity of C12H25N(CnH2n+1)3Br and its mixture with C12H25OSO3Na has been studied by surface tension method. The composition of the surface adsorption layers, micelles and molecular interaction parameters have been calculated according to the regular solution theory. The effect of polar group size has been investigated emphatically. It shows that the polar group size exerts a remarkable effect on the single C12H25N(CnH2n+1)3Br systems─— with the increase of n, cmc’s decrease successively; and γcmc’s increase at first(n=1-2) and then decrease(n=2-4). This effect can be interpreted in terms of the steric hindrance, hydrophobic effect, HC-chain bending effect, and charge screening of the polar group moiety. In the mixthre of C12H25N(CnH2n+1)3Br and C12H25OSO3Na, the effect of polar size is less obvious.

Key words: Dodecyltrialkylammonium bromide, Polar group eddect, Cationic-nionic surfactants, Surface activity