鐵-氧化鐵奈米粒子之合成及研究

Abstract

本論文旨在第一部份為利用逆微胞法合成鐵-氧化鐵核殼奈米微粒，並利用穿透式電子顯微鏡/能量分析光譜/電子能量損失光譜/能量濾波能量系統 (TEM/EDS/EELS/EFTEM)探討此奈米微粒之結構與組成。此外，利用XPS可以明確確認出在奈米粒子核部份為零價金屬鐵的存在，外層為氧化鐵，氫氧基(-OH)則分佈於奈米粒子表層。在第二部份中，藉由超導量子干涉磁量儀（SQUID磁量儀）量測出的磁滯曲線（磁化率對磁場之曲線），判斷此鐵-氧化鐵核殼奈米微粒在常溫及低溫下之磁性種類，由ZFC-FC曲線（磁化率對溫度之曲線）可得到其磁性轉化溫度(Blocking temperature, Tb)。第三部份則為探討利用表面修飾技術，使鐵-氧化鐵核殼奈米微粒可分散於不同極性之溶劑中。第四部份為利用塊式高分子自組裝微結構的特性，合成出鐵-氧化鐵核殼奈米微粒/自組裝塊式高分子奈米複合材料，並探討其奈米微結構及此鐵-氧化鐵核殼奈米微粒之分散情形。最後將已合成好的鐵奈米粒，選擇性分散在雙塊式高分子之其中一相中，外加磁場，誘導塊式高分子順著外加磁場方向產生大面積規則排列。

In this thesis, iron/iron oxide core-shell nanoparticles have been prepared successfully by a reversed-micelle method. After purification by magnet and centrifuge, the core-shell structure of iron/iron oxide nanoparticles was characterized by transmission electron microscopy (TEM). The oxidation state and the composition of the nanoparticles were determined by energy dispersion spectrum (EDS), electron energy loss spectrum (EELS), energy-filtered TEM image (EFTEM), and X-ray photoelectron spectrum (XPS). Magnetization measurements were performed with M-T and M-H curves on a Superconducting Quantum Interference Device (SQUID) magnetometer. The iron-iron oxide nanoparticles can be dispersed in pyridine by the dipole-dipole interactions between the hydroxyl groups and the pyridine molecules. Moreover, a hydrophilic surface of the particles can be obtained by the surface modification with olic acid as the surfactant. The self-assembled iron-iron oxide/PS-P4VP block copolymer nanocomposites have be prepared in pyridine. The iron-iron oxide nanoparticles can be sequestrated selectively in the P4VP domains of PS-P4VP bulk samples and thin films. The structural long-rang orientation of the nanocomposites could be obtained by the application of a magnetic field.