Saturday Science Sessions – Liquid Magnets
A liquid magnet or ‘ferrofluid’ is a mixture of magnetic particles on the nanometer scale, suspended in a liquid solution. This solution prevents the magnetic particles from sticking together. In this case, toner from a fax machine was mixed with a small amount of olive oil (hurray for a Staples recycle bin full of toner cartridges!). Other possibilities include magnetite suspended in kerosene.
The particles in this mixture alone have a totally random orientation if a magnetic field is not present. When a magnet is brought to the sides of the container with the mixture, an external magnetic field acts on the particles. Attractive forces allow the mixture to move where the magnet is moved.
This experiment definitely needs another attempt with stronger magnets!