National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, People's Republic of China.
Nanotechnology. 2011 Jun 3;22(22):225604. doi: 10.1088/0957-4484/22/22/225604. Epub 2011 Apr 1.
Monodisperse superparamagnetic Fe(3)O(4)/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe(3)O(4)/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe(3)O(4)/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe(3)O(4) nanoparticles. VSM and TGA showed that the Fe(3)O(4)/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g(-1) (total mass), which was only decreased by 17% compared with the initial bare Fe(3)O(4) nanoparticles.
通过一种简便的新型细乳液聚合方法，成功制备了具有高饱和磁化强度的单分散超顺磁 Fe(3)O(4)/聚甲基丙烯酸甲酯(PMMA)复合纳米球。将铁磁流体、MMA 单体和表面活性剂共同进行超声乳化，形成用于聚合的稳定细乳液。通过 DLS、TEM、FTIR、XRD、TGA 和 VSM 对样品进行了表征。通过 DLS 得到的 Fe(3)O(4)/PMMA 复合纳米球的直径接近 90nm，相应的多分散指数(PDI)低至 0.099，这表明纳米球在水介质中具有极好的均一性。TEM 结果表明，Fe(3)O(4)/PMMA 复合纳米球具有完美的核壳结构，PMMA 壳层约 3nm 厚，核由许多均匀且紧密堆积的 Fe(3)O(4)纳米颗粒组成。VSM 和 TGA 表明，至少含有 65%高磁铁矿含量的 Fe(3)O(4)/PMMA 复合纳米球具有超顺磁性，饱和磁化强度高达约 39emu g(-1)(总质量)，与初始的 bare Fe(3)O(4)纳米颗粒相比仅降低了 17%。
