物理化学学报 >> 1987, Vol. 3 >> Issue (02): 129-135.doi: 10.3866/PKU.WHXB19870205

研究论文 上一篇    下一篇

反离子对胶团生长影响的研究

吴佩强; 柳萍; 周祖康   

  1. 北京大学物理化学研究所
  • 收稿日期:1985-11-14 修回日期:1986-04-07 发布日期:1987-04-15

SPECIFICITY OF SOME COUNTER IONS TO INDUCE THE GROWTH OF MICELLES

Wu Peiqiang; Liu Ping; Zhou Zukang   

  1. Laboratory of Colloid Chemist; Institute of Physical Chemistry; Peking University
  • Received:1985-11-14 Revised:1986-04-07 Published:1987-04-15

摘要: 本文采用粘度法研究反离子对胶团生长的影响。通过粘度测量, 利用Missel等提出的热力学模型, 求算了支配球-棒转变的平衡常数K和胶团的重均聚集数n_w. 同价反离子促使溴化十四烷基吡啶胶团长大的能力为ClO_3~->NO_3~->Br~-. 在0.5 molL~(-1)的NaBr和KNO_3的介质中, 参数K在一定的胶团浓度范围内保持为常量, K值与n_W值随活性剂浓度的变化, 与光散射相应结果相当一致; 在0.5 molL~(-1)KClO_3介质中, K值明显地有浓度依赖性, 所得n_W值两法相差较大, 上述模型不再适用。

Abstract: Viscosity measurements havebeen made to determine the specificity of some counterions to induce the growth of micelles. From the intrinsic viscosity values abtained several basic micellar parameters including the thermodynamic parameter K, governing the sphere-to-rod transition in the micelle growth process, and the weight average aggregation number of polydisperse micelles, n_w, were calculated based on a thermodynamic model for micellization developed by Missel et al. The elongation of tetradecylpyridinium bromide micelles in aqueous solutions are induced by the monovalent anions Br~-, NO_3~-, ClO_3~-, the efficiency is ClO_3~->NO_3~->Br~-. In both 0.5 mol L~(-1) NaBr and KNO_3 Solutions a constancy of K was observed over a suitable range of ampnipnile concentrations. The parameter K as well as the parameter n_w calculated as a function of amphiphile concentrations are in good agreement with those obtained by static and dynamic light scattering techniques. In 0.5 mol L~(-1) KClO_3 solution, the parameter K becomes remarkably concentration-dependent and an obvious discrepancy in the determined parameter n_w between the two methods is observed, which demonstrates the invalidity of the model.