Multiresponsive Properties of Triple-Shell Architectures with Poly(N,N-diethylaminoethyl methacrylate), Poly(N-vinylcaprolactam), and Poly(N,N-dimethylaminoethyl methacrylate) as Building Blocks

Triple-shell architectures, consisting of poly[(N,N-diethylaminoethyl methacrylate)-block-(N-vinylcaprolactam)-block-(N,N-dimethylaminoethyl methacrylate)] triblock copolymers, are obtained by sequential reversible additionfragmentation chain transfer polymerizations, using a terminal-modified hyperbranched poly(beta-cyclodextrin) core as a macro chain transfer agent. UV-vis spectroscopy results indicate that the triple-shell architectures possess one pH response at pH 12.5 in aqueous solution at room temperature, followed by double-temperature- responsiveness between 33 degrees C and 36 degrees C. The special multiresponsive properties are further confirmed by investigating the controlled release behavior of the resulting polymers using metronidazole as a model drug.