Study on Synthesis and Properties of Magnetic Nanoparticles/Block Copolymer Composite

• Main Authors: Chun-Jung Chao, 趙俊榮
• Other Authors: Chieh-Tsung Lo
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/58311979484683000226

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 97 === Fe3O4 nanoparticles were prepared by thermolysis using TOPO as a surfactant and Fe(CO)5 as a precursor. Transmission electron microscopy, X-ray diffraction and superconducting quantum interference device were employed to characterize the size, structure and magnetic properties of these particles. It was obtained that Fe3O4 nanoparticles synthesized by heating mantle system exhibited smaller size and lower magnetization than those by oven system. In addition, the synthesis of particles without argon flow caused the increasing particle size and decreasing magnetization. The effect of the magnetic properties of nanoparticles on the phase behavior of polymer nanocomposite composed of as prepared Fe3O4 particles and polystyrene-b-poly(2-vinylpyridine) (PS-P2VP) diblock copolymer was studied. Because Fe3O4 nanoparticles were modified with TOPO, particles prefer to locate in the P2VP domains. However, the aggregation of nanoparticles occurred with increasing particle concentration due to the strong magnetic interaction between particles. This caused the disordering of composite. The critical particle concentration to induce the order-disorder transition of composite increases with decreasing particle size and magnetism. Fe3O4-Au core-shell nanoparticles were prepared using Fe3O4 as seeds. The thickness of Au shell can be manipulated by varying the concentration of Au precursor. The UV-Vis spectra of these core-shell particles showed a strong function of the Au shell thickness.