2004 Volume 4 Issue 12 Pages 509-517,491
Reversible formation control of surfactant molecular assemblies (micelles, worm-like micelles, vesicles, etc.) by external stimuli has been a subject of significant attention because it can be applied to controlled release of encapsulated drugs and perfumes and/or removal of organic impurities dissolved in water. This study deals with photochemical control of molecular aggregate formation with a “photo-switchable” cationic surfactant modified with azobenzene (AZTMA).
First, photochemical control of solubilization was described by making use of difference in cmc and solubilizing capacity between trans-AZTMA and cis-AZTMA. Next, solution viscosity was reversibly controlled by trans-cis isomerization of AZTMA incorporated in worm-like micelles. Finally, photo-chemical control of vesicle formation using an AZTMA/SDBS catanionic system was described. In addition, uptake and release of water soluble and/or insoluble drugs encapsulated in molecular assemblies were studied.
