双重磁响应温敏复合微球的制备及表征

Preparation and Characterization of Thermo-Sensitive Composite Microspheres with Dual-Magnetic Responses

在Fe3O4纳米粒子表面聚合包覆温敏性聚N-异丙基丙烯酰胺(PNIPAM)及其与聚苯乙烯(PS)、聚α-甲基丙烯酸(PMAA)的共聚物,制备表面不同亲水/疏水性质的双重磁响应温敏复合微球。利用透射电镜(TEM)、红外光谱(FT-IR)及Zeta粒度仪(DLS)等对复合微球进行了表征。结果表明,复合微球呈现核壳结构,粒径约为150nm^300nm;在复合微球温敏聚合物中引入亲水/疏水链段可以有效调节其最低临界溶解温度(LSCT),随着温敏聚合物亲水性的提高,微球LSCT向高温移动,且该微球具有良好的双重磁响应特性(磁靶向响应性和磁热响应性)。

Fe3O4 nanoparticles were encapsulated with various thermo-sensitive polymer including poly （N- isopropylacrylamide）, poly（N-isopropylacrylamide-co-styrene） and poly（N-isopropylacrylamide-co-methacrylic acid） to form thermo-sensitive composite-microspheres with dual-magnetic responses. The composite-microspheres were characterized by transmission electron microscope （TEM）, Fourier transform infrared spectra（FT-IR） and dynamic light scattering （DLS）. The results indicate that the composite-microspheres are characterized with a magnetic Fe3O4 core, a polymer shell, and an average diameter of about 150 nm-300 nm. The lower critical solution temperature （LSCT） of composite-microspheres can be controlled by introduction of different polymer-units （hydrophilic or hydrophobic） onto thermo-sensitive poly （N-isopropylacrylamide） chains, and the LSCT moves to higher temperatures as the contents of hydrophilic polymer-units increase. Besides, the above composite-microspheres also possess dual-magnetic responses （including magnetic delivery and magnetic-thermal effects）.