热响应性聚合物包覆铜纳米粒的研制和性能

Development and performance of Cu nanoparticles coated with thermorsensitive polymers

以聚乙烯亚胺(PEI)、N-异丙基丙烯酰胺(NIPAM)为单体,无皂乳液聚合法制备了热响应性聚乙烯亚胺(PNIPAM-PEI),分散于一定浓度Cu2+溶液,原位还原,制得温敏性聚合物包覆铜的复合颗粒。扫描电镜观察发现,复合颗粒形态规则、分布均匀,较低Cu2+浓度制备颗粒粒径比较高浓度的小。热分析显示,复合颗粒最终残留物质量分别可达35%和47%,表明有较好聚合物包覆率。红外光谱、X衍射对样品组成分析发现,样品中有未被完整包覆的Cu颗粒存在。紫外可见分光光度仪测定复合颗粒分散液温敏性显示,吸光度随温度有明显变化,显示较好的温度响应性。

Poly （ethylene imine） and N-isopropylacylamide were Used as monomers of polymerization reac- tion, a temperature-sensitive grafting copolymer of poly （ N-isopropylacylamide ） -g-poly （ ethylene imine） is synthesized with surfactant-free emulsion polymerization. The temperature-sensitive polymer was dispersed in a certain concentration of Cu2 ＋solution, and then a composite particles of the copolymer coating copper nanoparticles were prepared by in situ reduction method. The observation results with scanning electron microscope showed that the composite particles presented a regular sphere morphology and uniform size distribution, and the average diameter with chemical reduction of low Cu2＋ concentration complexes was less than that of high Cu2＋ concentration. Thermogravimetric measurements indicated that coating copoly- mer amount and residual mass in the particles were above 35% and 47% ,respectively,implying a better coating ratio to Cu. Fourier transform infrared spectroscopy and X-ray diffraction analysis revealed that some composite particles had not be coated entirely Cu by the copolymer. The temperature sensitivity of dispersed solution from the composite particles was measured using UV-visible spectrometer. The results indicated that the absorbance created obviously an abrupt change with increasing temperature, implying better temperature responsivity.