Preparation of Dilution-stable Aqueous Magnetic Fluids.
Pres At 2D Internat Conf on Magnetic Fluids Orlando Florida 1980 Mar; :6 pages
The extension of the Bureau-developed peptization technique for kerosine-base fluids to the preparation of the aqueous variety was possible when oleic acid was replaced by dodecylamine. The fluids thus prepared were, however, not stable toward dilution. When dodecanoic (lauric) acid was used instead of dodecylamine as the dispersing agent, the resulting aqueous magnetic fluid was found to be more stable toward dilution with water. In this second generation water-base magnetic fluid, the dodecanate anionic dispersing agent is superior to the commonly used dodecylamine cationic dispersing agent. Chemisorption of dodecanate anion on the magnetite surface proper by chemically bonding to surface iron atoms is contrasted to the mere adsorption of a cationic surfactant on the solution side of the electric double layer.
Pres. At 2D Internat. Conf. on Magnetic Fluids, Orlando, Florida, Mar. 24-27, 1980 IEEE Trans.