Redox, Ionic Strength, and pH Sensitive Supramolecular Polymer Assemblies.

Supramolecular complex of a cationic surfactant and oppositely charged disulfide containing polyelectrolyte was found to form micelle type aggregates at concentration much lower than the critical aggregate concentration (CAC) of the surfactant itself. We show that this difference can be utilized to generate stimulus-sensitive disassembly of these structures. This can be achieved either by converting the polyelectrolyte counterions to monovalent counterions in response to a stimulus or by simply weakening the interaction between the polymer and the surfactant in the presence of a stimulus. We have utilized three different stimuli to demonstrate these possibilities.

Tunable disassembly of micelles using a redox trigger.

A simple design for stimuli-responsive micellar disassembly has been demonstrated on the basis of a surfactant molecule wherein the hydrophilic head group is connected to the hydrophobic tail through a redox-sensitive disulfide linker. The disassembly kinetics is tuned by mixing the stimuli-responsive surfactant with a suitable nonresponsive co-surfactant in various ratios, which helps in gaining control over the release rate of encapsulated dye molecules from such mixed micelles.