磁性流體之製備與特性研究

A Study on the Preparation and Characteristics of Magnetic Fluids

蔡敏行(Min-Shing Tsai) ； 蔡煥修(Huahn-Shiou Tsai)

《鑛冶：中國鑛冶工程學會會刊》 37卷2期 (1993/06) Pp. 115-124

摘要

本研究之結果顯示，合成Fe_3O_4磁粒時，在室溫下、Fe^(2+)起始濃度0.25M、Fe^(2+)／Fe^(3+)＝2／3、R≧6可得粒徑70－90Å，飽和磁化量63emu／g之共沉物。製備磁性流體時，對10.0g Fe_3O_4磁粒，添加1.5g之十二酸，在磁粒表面會形成單層之化學吸附，可在煤油中製得油基磁性流體。當十二酸之添加量為3.0g，為單層吸附添加量之兩倍時，在氨水調整pH9－11之水溶液中可一次完成化學與物理之兩層吸附層，獲得安定分散式之水基磁性流體，所製得之水基磁性流體，比重由1.04變化至1.30時，比黏度由1.35變化至6.03，其飽和磁化量亦可達21.15emu／g。

並列摘要

The result of this study indicates that in preparing submicron magnetic particles of Fe_3O_4, from initial concentraction of Fe^(2+) =0.25M, Fe^(2+)/Fe^(3+)=2/3, R≧6, the particles of diameter 70-90Å, 63 emu/g of saturated magnetization were created. With regard to 10.0g Fe_2O_3, the dosage of lauric acid 1.5g is needed to complete the chemical coating in preparation of oil-based magnetic fluid , and the dosage 3.0g in needed to complete the chemical and physical coating simultaneously under ammonium solution of pH=9-11 in preparation of water-based magnetic fluid. The specific gravity of obtained water-based magnetic fluids change from 1.04 to 1.30 and relative viscosities from 1.35 to 6.03, and the applied magnetic field is 13.3kOe, saturated magnetization is increased from 4.2 emu/g to 21.2 emu/g.