温敏性P(St-NIPAM)/PNIPAM-Ag复合微凝胶制备及性能研究

Preparation and Properties of Thermosensitive P(St-NIPAM)/PNIPAM-Ag Composite Microgels

通过无皂乳液聚合和种子乳液聚合两步法合成苯乙烯与N-异丙基丙烯酰胺共聚物/聚N-异丙基丙烯酰胺[P(St-NIPAM)/PNIPAM]核-壳结构复合微凝胶,再以其为模板在硝酸银水溶液中充分溶胀,并以乙醇为还原剂,在NH3气氛条件下还原,制备得到高分子微凝胶负载纳米银P(St-NIPAM)/PNIPAM-Ag的复合微凝胶材料.通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FT-IR)、X射线衍射仪(XRD)、热分析(TGA)、紫外-可见分光光度计(UV-vis)、激光粒度分析等手段对复合微凝胶进行结构、组成和性质表征.研究结果表明,复合纳米银后的P(St-NIPAM)/PNIPAM-Ag复合微凝胶仍具有温敏性,且其温度敏感性随壳层中复合纳米银含量的增加而减弱.P(St-NIPAM)/PNIPAM-Ag复合微凝胶对对硝基苯酚的还原反应具有良好的催化活性,在45 min内基本将对硝基苯酚催化还原为对氨基苯酚.

Poly（styrene-co-N-isopropylacrylamide）/poly（N-isopropylacrylamide） [P（St-NIPAM）/PNIPAM] composite microgels with core-shell structures were synthesized by two-step reaction including a surfac-tant-free emulsion polymerization and a seed emulsion polymerization method.P（St-NIPAM）/PNIPAM composite microgels were fully swollen in AgNO3 aqueous solution.Using alcohol as reducing agent,P（NIPAM-St）/PNIPAM-Ag composite microgels loaded with Ag nanoparticles were prepared in the atmos-phere of ammonia gas via polymer microgel template technique.The structures,components and properties of the prepared composite microgels were characterized by scanning electron microscope（SEM）,transmis-sion electron microscope（TEM）,Fourier transform infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,thermogravimetric analysis（TGA）,UV-visible spectrophotometer（UV-vis） and laser particle size analyzer.It was demonstrated that P（St-NIPAM）/PNIPAM-Ag also showed thermosensitivity,and the thermosensitiv-ity was weaken with the inceasing of the loading amount of Ag nanoparticles on the shell layer.P（St-NIPAM）/PNIPAM-Ag composite microgels as a catalyst has excellent perfomance for reduction 4-nitrophenol（4-NP） to 4-aminophenol（4-AP） within 45 min.