Light-responsive terpolymers based on polymerizable photoacids
We present the synthesis and characterization of amphiphilic terpolymers containing photoacids based on 1-naphthol using reversible addition fragmentation chain transfer radical polymerization (RAFT). The respective poly(methyl methacrylate-co-2-(N,N-dimethylamino)ethyl methacrylate-co-1-naphthol methacrylate/methacrylamide) P[MMAx-co-DMAEMAy-co-NMAz/NMAmz] terpolymers were prepared starting from 1-naphthol derived monomers tNMA and tNMAm via RAFT polymerization und subsequent deprotection of the hydroxyl groups. The resulting materials were characterized using size exclusion chromatography and UV/Vis absorption spectroscopy, the latter also enabling the determination of pKa in the ground as well as the excited state of the monomers (NMA and NMAm). Afterwards, nanoprecipitation led to the formation of nanoparticles in aqueous media, which exhibited photo-responsive behavior upon UV-irradiation. Nile Red was encapsulated into the nanoparticles as a model hydrophobic guest molecule and we could demonstrate light-triggered release.