Method of preparing low viscosity, electrically conductive ferrofluid composition
AssigneeFerrofluidics Corporation
InventorsLucian Borduz, Kuldip Raj
Life of this patent
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Abstract
A low viscosity, electrically conductive ferrofluid composition and method of making and using same, which composition comprises: a first polar liquid carrier; a second polar liquid carrier miscible in the first polar carrier and comprising a polyol, such as a tetraethylene glycol dimethyl ether; magnetic particles to impart magnetic characteristics to the ferrofluid composition; and a surfactant, particularly a cationic surfactant in an amount sufficient to stabilize and disperse the magnetic particles, the surfactant dissociated or ionized predominately by the second polar liquid carrier.
Claims13
A method of preparing a low viscosity, electrically conductive ferrofluid composition, which method comprises:
- (a) dispersing magnetic particles in an amount sufficient to provide magnetic properties in a polar liquid carrier in the presence of a surfactant to provide a ferrofluid composition;
- (b) the improvement which comprises:
- (i) adding to the ferrofluid composition a dissociation or ionizing amount of a dissociation or ionizing agent for the surfactant to provide a ferrofluid composition having an electrical resistivity of 1.times.10.sup.7 ohms-centimeters or less, the agent consisting of an oxygen-containing agent selected from a group consisting of an alkylene polyol, an ether of an alkylene polyol and combinations thereof.
Dependencies are inferred from the claim text.