Azobenzene-Containing Molecularly Imprinted Polymer Microspheres with Photo- and Thermoresponsive Template Binding Properties in Pure Aqueous Media by Atom Transfer Radical Polymerization
作者：Liangjing Fang, Sujing Chen, Xianzhi Guo, Ying Zhang, Huiqi Zhang*
關鍵字：Molecularly imprinted polymers, azobenzene, photoresponsive, thermoresponsive, aqueous media, atom transfer radical polymerization
論文來源：期刊
具體來源：Langmuir 2012, 28(25), 9767-9777.
發表時間：2012年
A facile, general, and highly efficient approach to obtain azobenzene (azo)-containing molecularly imprinted polymer (MIP) microspheres with both photo- and thermoresponsive template binding properties in pure aqueous media is described for the first time, which involves the first synthesis of "living" azo-containing MIP microspheres with surface-immobilized alkyl halide groups via atom transfer radical precipitation polymerization (ATRPP) and their subsequent modification via surface-initiated atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAm). The successful grafting of poly(NIPAAm) (PNIPAAm) brushes onto the obtained MIP microspheres was confirmed by FT-IR, SEM, water dispersion stability and static contact angle studies, and template binding experiments. The introduction of PNIPAAm brushes onto the azo-containing MIP microspheres significantly improved their surface hydrophilicity and imparted thermoresponsive properties to them, leading to their pure water-compatible and thermoresponsive template binding properties. In addition, the binding affinity of the imprinted sites in the grafted azo-containing MIP microspheres was found to be photoresponsive toward the template in pure water, and this photoregulation process proved to be highly repeatable under photoswitching conditions.