磁性Fe_3O_4微粒表面有机改性

Surface Organic Modification of Magnetic Iron Oxide Black Particles*

在分散聚合法制备复合磁性微球过程中 ,采用硅烷偶联剂 KH- 570对磁性 Fe_3O_4微粒进行表面改性 .红外光谱 (FTIR)、光电子能谱 (XPS)分析结果表明 ,偶联剂与磁性微粒表面以化学键形式结合 .改性后 ,Fe_3O_4微粒与单体及其聚合物之间具有良好的亲和性 ,采用改性后的磁性微粒可以显著改善磁性微球的性能指标 .

The affinity between magnetic particles (Fe3O4) and monomer or its polymer is a key factor affecting the function of micro-spheres in the preparation of encapsulated magnetic micro-spheres(EMMS), Silane coupling[KH-570, CH2C(CH3)C(O)OC3H6Si (OCH3)(3)] was used for the surface modification of fine magnetic particles with 0.2 similar to 0.3 mum in size and tetrahedron in crystal form. Ethanol/water solution was used as modification medium for silane coupling. Fourier transform infrared spectrometer and X-ray photoelectron spectra analysis show that the coupling bonds chemically on the particle surface, leading to the affinity improvement between magnetic particles and monomer or its polymer. The encapsulated magnetic microspheres synthesized by dispersion polymerization of styrene in the presence of modified Fe3O4 particles are significantly improved compared with that when unmodified Fe3O4 particles are used.