| Title |
Dispersion Mechanism of the Water - Based Magnetic fluids by Peptization Method |
| Authors |
김민석(Min Seuk Kim); 김만(Mahn Kim); 오재현(Jae Hyun Oh); 강남기(Nam Kee Kang) |
| Abstract |
Water-based magnetic fluids were successfully prepared using the synthesized ultrafine magnetite coated with fatty acid. The effect of pH change on the stability of dispersion in water-based magnetic fluids was investigated and the results were obtained as follows; The dispersion ratio of magnetic fluids stabilized by decanoic acid was constantly maintained over 95% when the amount of decanoic acid for magnetite of 20g was more than 0.035㏖. It was 2.2 times as much as the amount for monolayer adsorption. The stable pH region for the magnetic fluids prepared with saturated fatty acid was in the range of 6.5 to 11.0. As the length of carbon chin of fatty acid is longer, the stable dispersion pH became higher. In decanoic acid stabilized magnetic fluid, there was a close inter-relationship with the amount of chemisorption. The dispersion mechanism of water-based magnetic fluid is proposed and it is consisted of the magnetite surrounded with double layer surfactants. |