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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (20): 2279-2284. 上一篇    下一篇

研究论文

囊泡形成和破坏的动力学

周文婷，徐晓明，蓝琴，韩国彬*   

  1. (固体表面物理化学国家重点实验室 厦门大学化学化工学院化学系 厦门 361005)
  • 投稿日期:2006-08-31 修回日期:2007-05-09 发布日期:2007-10-28
  • 通讯作者: 韩国彬

Kinetics of Vesicle Formation and Breakdown

ZHOU Wen-Ting ;XU Xiao-Ming; LAN Qing; HAN Guo-Bin*   

  1. (State Key Laboratory for Physical Chemistry of Solid Surface and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005)
  • Received:2006-08-31 Revised:2007-05-09 Published:2007-10-28
  • Contact: HAN Guo-Bin

PDF

1221

被引次数

7

利用停流装置研究了十二烷基硫酸钠(SDS)和十二烷基三甲基溴化铵(DTAB)复配形成囊泡的过程和囊泡破坏过程的动力学性质, 并结合动态光散射技术和电子透射显微镜探索囊泡形成和囊泡破坏过程的机理. 动态光散射和电子透射显微镜的研究结果表明囊泡的形成过程主要包括四个阶段: 混合胶团→柔性的长棒状聚集体→“非平衡囊泡”→平衡囊泡, 而与其对应的粒度分散度则呈现“单分散性→多分散性”的周期性变化规律. 此外, 动力学结果表明囊泡形成过程很长, 但其活化能不大, 这意味着囊泡形成过程的控制步骤可能不是活化能控制. 而相对于囊泡的形成, 囊泡的破坏过程是十分迅速的.

关键词: 囊泡, 表面活性剂, 停流法, 临界堆积常数

A combination of stopped-flow, transmission electron microscopy and dynamic light-scattering techniques has been used to study the kinetics of vesicle formation and breakdown as well as the mechanism of vesicle formation and breakdown in DTAB/SDS aqueous solutions. The results show that the process of vesicle formation can be modeled as a sequence of distinct processes: mixed micelles→flexible stick-shaped aggregates→non-equilibrium vesicles→equilibrium vesicle system, and the evolution of particle dispersion degree appears to be a periodical change of “monodispersity→polydispersity”. In addition, the kinetic analysis shows that the process of vesicle formation lasts for a long time. However, the activation energy of vesicle formation is not too high, which implies that the control procedure of the process is independent of activation energy. In contrast to the process of vesicle formation, vesicle breakup to mixed micelles appears to be a rapid process.

Key words: vesicle, surfactant, stopped-flow method, effective packing parameter