Ferro Fluid is a colloidal suspension of nano scale magnetic particles in a liquid carrier. The particles average about 10nm in size and are coated with a dispersing agent (surfactant) to prevent agglomeration. Normally, the particles are randomly distributed, but in the presence of a magnetic field, each particle aligns along the magnetic force lines so that the fluid behaves as a homogeneous magnetic liquid that responds instantly to changes in the strength and orientation of the magnetic field.
Ferro Fluid is a novel application of nano technology that was originally developed to control liquid fuel flow in space, and is now used in many commercial applications including computer hard drives, audio speakers, bio-medical procedures and detection of micro-faults in critical steel components. Now you can use Ferro Fluid to demonstrate and discuss magnetic behaviour in your classroom.
Liquid medium: mineral oil
Magnetic particles: magnetite (Fe3O4)
Saturation magnetization: 400 gauss
Density: 1.21 g.cm-3
Viscosity: 6 cp at 27oC
Surface tension: 29 dynes.cm-1