Multistimuli Responsive Polymer Nanoparticles On the basis of the Amphiphilic Azobenzene-Contained Hyperbranched Poly(ether amine) (hPEA-AZO)

Abstract

We here reported the multistimuli responsive behavior of polymer nanoparticles, which was formed through direct dispersion of the amphiphilic azobenzene-contained hyperbranched poly(ether amine) (hPEA-AZO) in water. A series of hPEA-AZO were synthesized by introduction of azobenzene moieties into the periphery of hyperbranched poly(ether amine) (hPEA), which was developed by our group recently. The obtained polymer nanoparticles of hPEA-AZO which were revealed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), exhibited the sharp stimuli-response to temperature, pH, and ionic strength with tunable cloud point (CP) from 25 to 100 °C. CP of the obtained hPEA-AZO nanoparticles in aqueous solution decreased with the increase of azobenzene content, pH value and ionic strength, and represented a linear relationship with the azobenzene content and ionic strength. The hPEA-AZO nanoparticles also showed a light-controlled CP and size. After UV irradiation (365 nm), we observed lower valu...