中华医学超声杂志

应用化学 ›› 1997, Vol. 0 ›› Issue (2): 40-44.

• 研究论文 • 上一篇    下一篇

溴化十二烷基吡啶的吸附和表面胶团化对二氧化硅悬浮液稳定性的影响

钱建刚, 顾惕人   

  1. 北京航空航天大学化学教研室, 北京 100083
  • 收稿日期:1996-07-26 修回日期:1997-01-04 出版日期:1997-04-10 发布日期:1997-04-10
  • 基金资助:
    国家自然科学基金

Effects of Adsorption and Surface Micellization of Dodecylpyridinium Bromide on the Stability of Silica Suspension

Qian Jiangang, Gu Tiren   

  1. Laboratory of Chemistry, Beijing University of Aeronautics and Astronautics, Beijing 100083
  • Received:1996-07-26 Revised:1997-01-04 Published:1997-04-10 Online:1997-04-10

PDF

416

被引次数

12 | 3

摘要： 研究了阳离子表面活性剂溴化十二烷基吡啶(DPB)的吸附和表面胶团化对二氧化硅(CAB-O-SIL)悬浮液稳定性的影响,以及加入电解质的效应。结果表明: DPB在CAB-O-SIL上的吸附等温线呈双平台(或LS)型,溴化钠(0.1mol/L)的存在使吸附等温线向低浓区移动,第二平台的饱和吸附量增大,但基本不影响第一平台的吸附量,这些结果都与涉及形成表面胶团的二步吸附模型相符。当DPB浓度很低时,CAB-O-SIL悬浮液的稳定性随DPB浓度的增大而下降;当DPB浓度增至smc(临界表面胶团浓度)附近时,悬浮液稳定性急剧提高。NaBr的存在,并不影响上述悬浮液稳定性规律。利用表面活性剂的二步吸附和颗粒相互作用模型,并结合DPB吸附等温线的研究结果,可以合理地解释CAB-O-SIL悬浮液稳定性的实验结果。

关键词: 二氧化硅悬浮液, 稳定性, 表面胶团化, 溴化十二烷基吡啶, 盐效应

Abstract: The effects of the adsorption and surface micellization of dodecylpyridinium bromide(DPB)on the stability of silica(CAB-O-SIL)suspension have been investigated. The adsorption isotherms of DPB on a flame hydrolyzed silica from aqueous solution exhibit two plateau(i.e.LS-type isotherm). In the presence of 0.1 mol/L NaBr the adsorption isotherm of DPB is displaced to lower equilibrium concentration region and the limiting adsorption is enhanced, but the adsorption in the first plateau remains nearly constant. In the low concentration range of DPB, the stability of silica suspension decreases with increasing concentration of DPB. However, near smc(surface micelle concentration)of DPB the stability increases sharply with increasing concentration of DPB. In the presence of NaBr, the stability of silica suspension is much lower in comparison with that without addcd salt. The results are explained in terms of the surface micellization model and the adsorption isotherms of DPB.

Key words: silica suspension, stability, surface micellization, dodecylpyridinium bromide, salt effect

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