Ho Kin Man, Li Pei
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China.
Langmuir. 2008 Mar 4;24(5):1801-7. doi: 10.1021/la702887m. Epub 2008 Jan 29.
A novel synthetic strategy was developed for the preparation of magnetic core-shell (MCS) particles consisting of hydrophobic poly(methyl methacrylate) cores with hydrophilic chitosan shells and gamma-Fe2O3 nanoparticles inside the cores via copolymerization of methyl methacrylate from chitosan in the presence of vinyl-coated gamma-Fe2O3 nanoparticles. The magnetic core-shell particles were characterized with transmission electron microscopy, field-emission scanning electron microscopy, particle size and zeta-potential measurements, vibrating sample magnetometry, and atomic force microscopy, respectively. The MCS particles were less than 200 nm in diameter with a narrow size distribution (polydispersity = 1.09) and had a good colloidal stability (critical coagulation concentration = 1.2 M NaCl at pH 6.0). Magnetization study of the particles indicated that they exhibited superparamagnetism at room temperature and had a saturation magnetization of 2.7 A m2/kg. The MCS particles were able to form a continuous film on a glass substrate, where magnetic nanoparticles could evenly disperse throughout the film. Thus, these new materials should be extremely useful in various applications.
通过在乙烯基包覆的γ-Fe₂O₃纳米颗粒存在下，使甲基丙烯酸甲酯与壳聚糖发生共聚反应，开发了一种新颖的合成策略，用于制备磁性核壳（MCS）颗粒，该颗粒由具有亲水性壳聚糖壳的疏水性聚（甲基丙烯酸甲酯）核以及核内的γ-Fe₂O₃纳米颗粒组成。分别用透射电子显微镜、场发射扫描电子显微镜、粒度和ζ电位测量、振动样品磁强计以及原子力显微镜对磁性核壳颗粒进行了表征。MCS颗粒直径小于200 nm，粒径分布窄（多分散性 = 1.09），并且具有良好的胶体稳定性（在pH 6.0时临界聚沉浓度 = 1.2 M NaCl）。对颗粒的磁化研究表明，它们在室温下表现出超顺磁性，饱和磁化强度为2.7 A m²/kg。MCS颗粒能够在玻璃基板上形成连续薄膜，磁性纳米颗粒可以均匀地分散在整个薄膜中。因此，这些新材料在各种应用中应该非常有用。
