自组装制备磁性复合微球聚集体

用部分还原法制得纳米Fe3O4，用微乳液聚合法制备聚（苯乙烯-丙烯酸）高分子微球P（St-co-AA），再以球形P（St-co-AA）为模板与Fe3O4磁粉通过静电自组装和氢键自组装制得磁性复合微球聚集体Fe3O4／P（St-co-AA）；利用XRD、TEM、SEM、IR等对样品进行表征，采用VSM对样品进行磁性能测试．结果表明所得样品为Fe3O4单相，平均粒径约10nm．P（St-co-AA）平均尺寸为约70nm，表面含有羧基，所制磁性复合聚集体Fe3O4/P（St-co-AA）的形貌为球形、多孔、粒径约5μm，磁粉含量为29％．磁性能测试表明当外加磁场为6KOe时，磁化强度达到饱和，饱和磁化强度为69emu.g^-1．研究表明pH、搅拌等对磁性复合微球聚集体的形成有重要影响．

Preparation of magnetic microsphere aggregates by self-assembly

Fe3O4 nanoparticles are synthesized by the partial reduction method, uniform P（St- co-AA） microspheres are prepared by microemulsion polymerization. The magnetic microsphere aggregates are prepared by electrostatic self-assembly and hydrogen bonding self-assembly with spherical P （St-co-AA） as template. The samples are characterized by X-ray diffraction（XRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, FTIR spectroscopy , magnetic properties measurement are performed by VSM. The results indicate that the magnetic powders with an average size of 10nm are single-phase Fe304. The polymer microsphere with earboxyl is ca.70nm. The spherical and porous Fe3O4/P（St- co-AA ）with an average size of 5μm are prepared by self-assembly. The contents of magnetic powders in Fe3O4/ P（St- co-AA ）are 29%. Magnetic properties measurement shows that magnetization of the magnetic powders get to saturation, and the saturated magnetization is 69emu.g^-1 when applied field is at 6KOe. The effects of pH, stirring on the preparation of aggregates have been investigated.