Synthesis of pH- and temperature-responsive chitosan-graft-poly(2-(N,N-dimethylamino)ethyl methacrylate) copolymer and gold nanoparticles stabilization by its micelles
作者：Weizhong Yuan*, Zhengda Zhao, Jinying Yuan, Shuying Gu, Fengbo Zhang, Xuming Xie, Jie Ren.
關鍵字：chitosan-graft-poly[2-(N,N-dimethylamino)ethyl methacrylate]; gold nanoparticle stabilization; pH- and temperature-responsive hybrid micelles
論文來源：期刊
具體來源：Polymer International, 2011, 60(2): 194-201
發表時間：2011年
Novel pH- and temperature-responsive chitosan-graft-poly[2-(N,N-dimethylamino)ethyl methacrylate] (chitosan-g-PDMAEMA) copolymers were successfully synthesized by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Chitosan macroinitiator was prepared by phthaloylation of amino groups of chitosan and subsequent acylation of hydroxyl groups of chitosan with 2-bromoisobutyryl bromide. The copolymers were obtained by ATRP of 2-(N,N-dimethylamino)ethyl methacrylate and they can self-assemble into stable micelles in water. Hybrid micelles with a PDMAEMA corona incorporating gold nanoparticles (Au NPs) were prepared in situ via the reduction of HAuCl4 with NaBH4. The pH and temperature responses of the copolymer micelles and hybrid micelles were characterized using UV-visible spectroscopy and dynamic laser light scattering. The morphology of themicelleswas observed using transmission electron microscopy and atomic force microscopy. The PDMAEMA corona of themicelles acts as the ‘nanoreactor’ and the ‘anchor’ for the in situ formation and stabilization of AuNPs. Therefore, the spatial distribution of Au NPs within the micelles can be tuned by varying the temperature and pH value.