Fusion and Fission Inhibited by the Same Mechanism in Electrostatically Charged Surfactant Micelles

详细信息    查看全文

• 作者：Yahya Rharbi ; M. Karrouch ; Paul Richardson
• 刊名：Langmuir
• 出版年：2014
• 出版时间：July 15, 2014
• 年：2014
• 卷：30
• 期：27
• 页码：7947-7952
• 全文大小：343K
• ISSN：1520-5827

文摘

This paper revises the general idea about the role of intermicellar and intramiceller interactions in inhibiting fusion of self-assembled surfactant micelles. Fusion and fission of micelles are usually thought to be limited by different mechanisms. While fission is accepted to be controlled by surface instabilities (intramicellar interactions), fusion is commonly thought to be rate limited by the barrier to the close approach between two micelles due to the steric or Coulombic repulsions (intramicellar interactions). Here we describe the role of electrostatic repulsions in inhibiting fusion and fission kinetics in self-assembled micelles. We use stopped flow-fluorescence technique with hydrophobic pyrene to quantify fusion and fission in ionic/nonionic mixed micelles (Triton X-100/SDS). We show that the fusion and fission rates decrease with the same tendency with increasing the fraction of the ionic charges, while their ratio remains constant. Our results are interpreted to mean that, in slightly charged micelles, fusion shares the same limiting step with fission, which most likely involves surface instabilities and intramiceller interactions.