| The goals of this project were to design and produce a radiopaque ferrofluid that was stable in a wide range of polar organic solvents. The ferrofluid produced should have physical properties that allow it to be hydrophobic, magnetically responsive, and capable of being seen by contrast imaging inside the body. A well known method for producing organic ferrofluids was employed. A 1:2 molar ratio of Fe2+/Fe3+ chloride salts were dissolved in degassed water and the pH of the resulting solution adjusted to ∼9.5 with ammonium hydroxide. The surfactant coating was then added in an organic solvent. As the mixture of magnetite and surfactant was stirred, the coated particles transferred to the organic phase. The layers were then separated and the organic soluble magnetic material collected and the organic solvent removed under vacuum.; The first ferrofluid investigated used oleic acid as the surfactant, and was soluble in organic solvents.; Several surfactants were examined leading to the discovery of a glycolic acid derivative with the desired solubility properties. (Abstract shortened by UMI.)... |
