ferrofluid chemical formula
The chemical formula for a ferrofluid is Fe(NO3)2. This is the equation for a fluid that becomes magnetic when it is exposed to a strong magnet.
Ferrofluids consist of nanoscale particles of iron or magnetite suspended in a liquid, typically an organic solvent or water. Each particle is coated with a surfactant that inhibits agglomeration of the particles due to van der Waals and magnetic forces.
In addition to prolonging the settling time of the magnetic particles, surfactants also reduce the packing density of the ferromagnetic nanoparticles while in the activated state of the fluid, decreasing their on-state viscosity, which is one of the most important parameters for users of these fluids (this is less of a concern when dealing with magnetorheological fluids).
A simple way to prepare a ferrofluid at home is to pour a bit of vegetable oil into a shallow dish, just enough to make a thin film across the bottom. Next, pour in some iron filings, and mix them until the oil and the filings become a thick sludge-like material.
If you put a magnet near the ferrofluid, it will quickly align with it and form spikes that will climb up the object, then cascade back down. This spiky appearance is what makes ferrofluids so interesting!