- 學位論文
以微波法製備四氧化三鐵磁性微粒之研究
A Study on the Preparation of Fe3O4 Magnetic Particles by Microwave
摘要
四氧化三鐵是亞鐵鹽尖晶石內中很重要的成分，已廣泛的被應用在儲存材料，顏料，光電繪圖顯影劑等等。目前有很多合成四氧化三鐵粒子的方法，像是在CO/CO2或H2的環境下還原赤鐵礦及利用共沉澱法在Fe2+/Fe3+混合的鹼性溶液中合成，要合成奈米四氧化三鐵跟其他氧化物一樣都必須先克服團聚現象的發生 本實驗的目的在利用微波輻射的過程中合成均勻的奈米四氧化三鐵粒子，選用硫酸亞鐵及氫氧化鈉作為前驅物，加入適量的分散劑進行微波，實驗中我們控制：(1)反應試劑的比例，(2)分散劑的量，(3)微波功率，(4)微波時間。最佳條件則是在微波功率600W且微波時間4分鐘時有最小粒徑、實驗的結果經由DLS、XRD、SEM 、TGA、SQUID能更了解合成之奈米粉体的特性。
並列摘要
Megnetite(Fe3O4)，an important member of spinel type ferrite，is used very widely for recording material，pigments and electrophotographic developer, etc﹒there are many method reported for the synthesis of Fe3O4 powders, e.g. reduction of hematite by CO/CO2 or H2, co-precipitation from the solution of ferrous/ferric mixed salt solution in alkaline medium﹒Synthesis of nano- Fe3O4 and some other oxides were reported elsewhere with serious aggregation problems. If agglomeration of the synthesized nano-particles could not been avoided, it is meaningless for any nano-oxide forming process no matter how small the particle size could be reached initially. Objective of the studies has been focused on the synthesis of uniform nano-oxides by a microwave irradiation process. Ferrous sulphate and sodium hydroxide were selected as the starting materials for the synthesis of nano- Fe3O4, then added a small amount of polymeric surfactants to make the particle not agglomerated . In the experiment, we control appropriate concentration of reagent, amount of dispersant, microwave heating time and power to synthesis uniform nano- Fe3O4. And infer the best condition that produces Fe3O4 nanoparticles by the experimental result. After the experiment , we can find that microwave heating time and power are 4 min and 600W respectively. The experimental results were characterized by Zeta sizer(DLS) , Scanning Electronic Microscopy (SEM),X-Ray diffractometer (XRD), Thermogravimetric analyzer(TGA),Superconducting Quantum Interfernce Device(SQUID)