功能性乙基纤维素复合微球的制备及性能

Preparation and Properties of Functional Composite Ethyl Cellulose Microspheres

中文关键词:  高压静电喷雾  温敏性  磁性  荧光  乙基纤维素微球

Key Words:high-voltage electrostatic spraying  thermo-responsiveness  magnetism  fluorescence  ethyl cellulose microsphere

中文摘要:

      将聚N-异丙基丙烯酰胺、Fe₃O₄纳米颗粒和染料4-甲胺基-9-烯丙基-1,8-萘酰亚胺与乙基纤维素溶液共混,利用高压静电喷雾技术一步法制得兼具温敏性、磁性和荧光性的乙基纤维素复合微球。结果表明,制备的乙基纤维素复合微球平均粒径在亚微米级,Fe₃O₄纳米颗粒的添加提高了复合微球的骨架强度和改善了微球形貌。当温度超过聚N-异丙基丙烯酰胺的低临界溶解温度时,乙基纤维素复合微球的平均粒径减小,表现出温敏性；基于微球的温敏响应,乙基纤维素复合微球表现出与染料溶液相反的温致荧光增强性能。振动样品磁强计分析结果表明,乙基纤维素复合微球具有良好的超顺磁性。

Abstract:

      Poly(N-isopropyl acrylamide) (PNIPAAM), Fe₃O₄ nanoparticles and dye 4-(methylamino)-9-methyl-1,8-naphthalimide (MMNI) were premixed with the solution of ethyl cellulose ethanol, and high-voltage electrostatic spraying technology was applied to prepare thermo-responsive, magnetic and fluorescent microspheres by one-step method. Results showed that the average particle size of the obtained ethyl cellulose microspheres was in submicron level. The addition of Fe₃O₄ increased the strength of microsphere skeleton and improved the morphology of microspheres. The average particle size of microspheres decreased as temperature exceeded the lower critical solution temperature of PNIPAAM, indicating the thermo-responsiveness of composite microspheres. Microspheres showed temperature-induced enhancement of fluorescence based on their thermo-responsiveness. Vibrating sample magnetometer analysis showed that the composite microspheres possessed good superparamagnetism．