pH/UV Responsive Polymeric Micelles Based on Coumarin to Tune Emulsification/Solidification Performance

Abstract

A kind of pH/UV sensitive terpolymer was prepared based on 2-(dimethylamino) ethyl methacrylate, hydroxyethyl methacrylate, and 7-(2-(4-vinylbenzyloxyl)-ethoxy)-4-methyl-coumarin. To well trace the self-assembly process and reversible photocross/de-cross-linking, the pH-and light-responsive behaviors at various conditions were investigated by dynamic light scattering and UV-Vis spectroscopic analysis, respectively. Besides, dual pH-and light-responsive coumarin-containing polymeric micelles could be used to manipulate the emulsion phases and trigger the solidification of emulsions, which was a big breakthrough in the development of particulate emulsifiers. The emulsifying performance could be predicted by the form of aqueous micellar solutions with a certain pH value before oil-water homogenization. Different to the effect of pH value lonely, the conversion from emulsification into solidification could be achieved with the synergetic effect of pH value and UV irradiation. This work might cast new insights on tuning emulsification/solidification performance just by adjusting pH value and UV irradiation time without the need for additives.[a] S.