Aggregation and pH Responsive Disassembly of a New Acid-Labile Surfactant Synthesized by Thiol-Acrylate Michael Addition Reaction

Nucleophilic thiol-acrylate Michael reaction between a hydrophobic thiol and hydrophilic acrylate derivative generated a nonionic surfactant with acid-labile beta-thiopropionate linker. Micellization of the surfactant, its ability to encapsulate hydrophobic dye, acid-induced disruption of the aggregate and pH-selective dye release profile have been revealed in this report. The micellar aggregates were found to be stable under neutral conditions, but they could be disrupted in acidic pH (5.3), and thus the encapsulated hydrophobic dye molecules could be selectively released. Appropriate control experiments revealed that the sulfur atom in the beta-position is essential for acidic hydrolysis of the ester functionality of the surfactant.