Hyperbranched Azopolymer with Quadruple Responsibility

• Published in: Chinese journal of polymer science 2021-09, Vol.39 (9), p.1169-1176
• Main Authors: Tian, Chen, Zhou, Ke-Cong, Lu, Yu-Fei, Li, Jin-Jie, Yao, Yuan, Tao, Xin-Feng, Zhuang, Qi-Xin, Xie, Yu-Feng, Lin, Shao-Liang
• Format: Article
• Language: English
• Subjects: Acidic oxides; Azo compounds; Azo polymers; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromophores; Condensed Matter Physics; Industrial Chemistry/Chemical Engineering; Micelles; Oxidation; Polyethylene glycol; Polymer Sciences; Polymers; Stimuli; Ultraviolet radiation
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-021-2576-1

Simply constructing multiple responsive polymers with obvious shape and dimension variations on their assemblies upon different stimuli is still rarely reported. In this study, we report a hyperbranched polymer named HPAzoBAHB- star -PEG 9 with quadruple-response to light, temperature, pH and oxidation stimuli. The polymer contains azobenzene chromophore, sulfide, amide and amine groups in its hydrophobic hyperbranched core, and the core is capped with hydrophilic polyethylene glycol (PEG 9 ) arms. HPAzoBAHB- star -PEG 9 could assemble into unusual leaf-like lamellar micelles at 25 °C under the guidance of orderly arranged H -aggregate of azobenzene moieties. These leaf-like lamellar micelles can transform into vesicles upon UV irradiation and lower temperature, or convert to smaller spherical micelles in acidic or oxidative environments, respectively, with the destroy of ordered azobenzene arrangements. This quadruple-responsive hyperbranched polymer is suitable to construct multiple stimuli-responsive micro/nanostructures, or accurate delivery and release following subtle stimuli sequences.