Abstract:
Two polymers, αCD and azobenzene modified poly(acrylic acid)s (αCDPAA and azoPAA) were prepared and characterized by 1HNMR. The photoresponsive polymer networks were prepared by macromolecular assembly based on the inclusion associations between azo and αCD grafts after mixing aqueous solutions of αCDPAA and azoPAA. Under irradiation of 365 nm UV light, viscosity of the network decreased by nearly one order of magnitude, while recovered after keeping the sample in dark for some time. The viscosity change was reversible and repetitive under UV irradiation and in dark. The viscosity change was due to the cis/trans transition of azo group under UV irradiation as studied by NMR and UVVis absorption spectra.