How to Make Liquid Magnets - Synthesize Ferrofluid. A liquid magnet or ferrofluid is a colloidal mixture of magnetic particles (~10 nm in diameter) in a liquid carrier. The carrier contains a surfactant to prevent the particles from sticking together. Ferrofluids can be suspended in water or in an organic fluid. A typical ferrofluid is about 5% magnetic solids, 10% surfactant, and 85% carrier, by volume. One type of ferrofluid you can make uses magnetite for the magnetic particles, oleic acid as the surfactant, and kerosene as the carrier fluid to suspend the particles. Several people have asked me if they can make substitutions for the oleic acid and the kerosene. The answer is yes, though changing the chemicals will change the characteristics of the ferrofluid somewhat.
When no external magnetic field is present the fluid is not magnetic and the orientation of the magnetite particles is random. You can find ferrofluids in high-end speakers and in the laser heads of some CD and DVD players. Ferrofluid. Sachiko kodama. Ferrofluid in shallow dish. Liquid Sound 3. Magnetic Thinking Putty. Non-Newtonian Fluid on a Speaker Cone. Ferrofluid Displays - CZFerro.