Junctions and end-caps in self-assembled non-ionic cylindrical micelles

✍ Scribed by N. Dan; S.A. Safran

• Book ID: 104011736
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 439 KB
• Volume: 123-126
• Category: Article
• ISSN: 0001-8686
• DOI: 10.1016/j.cis.2006.05.027

✦ Synopsis

Cylindrical micelles are known to exhibit two types of morphologies: branched networks and linear, worm-like (or thread-like) micelles. These structures correspond to two types of topological defects: end-caps and junction points. Although either type of defect increases the micelle energy (when compared to the cylindrical sections), they are stabilized by an increase in the translational (end-caps) or configurational ( junctions) entropy. End-caps reduce the length of the cylindrical micelles, resulting in a suspension of linear, worm-like micelles. Y-junction branch points cause the formation of a network structure that may percolate and coexist thermodynamically with a "sol" of finite cylinders with end-caps. In this paper, we review current experimental and theoretical studies of non-ionic cylindrical micelles in aqueous solutions. We focus on single and multicomponent amphiphiles, and consider both small molecules and macromolecules ( polymers), in order to identify the driving forces that determine the type of topological 'defect' and the resulting system morphology.