Thermoresponsive hydrogel of poly(glycidyl methacrylate-co-N-isopropylacrylamide) as a nanoreactor of gold nanoparticles
writer：Jiang, Xiaowei; Xiong, De'an; An, Yingli; 等.
keywords：hydrogel
source：期刊
specific source：JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
Issue time：2007年
onlinelibrary.wiley.com/doi/10.1002/pola.22037/abstract
The synthesis of a thermoresponsive hydrogel of poly(glycidyl methacrylate-co-N-isopropylacrylamide) (PGMA-co-PNIPAM) and its application as a nanoreactor of gold nanoparticles are studied. The thermoresponsive copolymer of PGMA-co-PNIPAM is first synthesized by the copolymerization of glycidyl methacrylate and N-isopropylacrylamide using 2,2′-azobis(isobutyronitrile) as an initiator in tetrahydrofuran at 70 °C and then crosslinked with diethylenetriamine to form a thermoresponsive hydrogel. The lower critical solution temperature (LCST) of the thermoresponsive hydrogel is about 50 °C. The hydrogel exists as 280-nm spheres below the LCST. The diameter of the spherical hydrogel gradually decreases to a minimum constant of 113 nm when the temperature increases to 75 °C. The hydrogel can act as a nanoreactor of gold nanoparticles because of the coordination of nitrogen atoms of the crosslinker with gold ions, on which a hydrogel/gold nanocomposite is synthesized. The LCST of the resultant hydrogel/gold nanocomposite is similar to that of the hydrogel. The size of the resultant gold nanoparticles is about 15 nm. The hydrogel/gold nanocomposite can act as a smart and recyclable catalyst. At a temperature below the LCST, the thermoresponsive nanocomposite is a homogeneous and efficient catalyst, whereas at a temperature above the LCST, it becomes a heterogeneous one, and its catalytic activity greatly decreases. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2812–2819, 2007