Intelligent light-responsive and ionic polymer functionalized polyacrylonitrile as an environmental benign catalyst for selective oxidation of benzyl alcohols. (January 2022)

• Record Type: Journal Article
• Authors: Hong, Peng; Wang, Limin; Bai, Linsheng; Liu, Zhongqiu; Liu, Yujing; Yang, Jianguo; Ying, Anguo
• Is Part Of: Dyes and pigments. Volume 197(2022)
• Publication Date: 2022-01
• Subjects: Polyacrylonitrile fiber -- Photo-responsive -- Microenvironment -- Oxidation -- Recyclability; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2021.109902
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Herein, spiropyran (SPA) and 1-vinyl-3-ethylimidazole were firstly grafted as conjugated polymer onto the Polyacrylonitrile fiber (PANF) by reversible addition fragmentation chain transfer (RAFT), and then their imidazole cation were used as exchanger to prepare an intelligent photo-responsive catalyst loaded with intact Keggin hydrogen phosphotungstate (Hx PW12 O40 (3−x) - ), which were fully characterized by FT-IR, XPS, SEM, TGA and ICP. The obtained catalysts could efficiently promote the aqueous oxidation of benzyl alcohol in presence of H2 O2 . The reversible light-responsive property of SPA on fiber renders its hydrophobic microenvironment which is propitious to adsorb organic starting substrates in the reaction process, while the increasing hydrophilicity, derived from the ring opening of SPA by ultraviolet light, can desorb the product completely from the fiber. The whole catalytic process, including reaction stage and work-up stage, does not need any volatile organic solvent and the catalysts could be recycled for 10 times without any significantly loss of activity. Finally, the fiber could be further twinned on the impeller of mechanical stirrer, demonstrating the readily scale-up production potential. Graphical abstract: Image 1 Highlights: Using RAFT, UV responsive fiber was prepared to catalyze the oxidation reaction. Hydrophobic SPA based fiber is favorable for adsorption of substrate and reaction. Ring opening of SPA by ultraviolet light can desorb product from the fiber. Whole catalytic process is absolutely solvent-free. Switchable fiber could be recycled for 10 times.