Ferrofluid - The "Smart" Fluid
In the video, a sharp-pointed ferrofluid sculpture is formed when electromagnet applies to it.
Isn't it fascinating?
Ferrofluid... What Is It?
Ferro means "Iron" in Latin. In short, Ferrofluid is ***Magnetite + Liquid medium + Surfactant*** Eg. Fe3O4 in Kerosene with Oleic acid
Ferrofluids are colloidal suspensions of magnetic fragments of iron oxide in a liquid medium.
As it contains magnetic fragments, it responses to magnetic field readily.
How Surfactant Works?
Grey: surfactant
black: iron oxide particle
yellow: oil particle
Surfactant grabs on iron oxide at one end and grabs the oil particle at the other end. When iron oxide is completely surrounded by surfactant, they are not able to clump together.
Application
There are many commercial applications for ferrofluids (rather than just as the pursue of arts). Here are some of the examples:
Protection for electrical devices
In speakers and hard drives, small amount of ferrofluid is placed between the magnets and shaft to prevent debris from entering the devices.
Heat Transfer
In addition, ferrofluid helps in heat transfer to avoid overheating.
Chemotherapy Ferrofluid is used to treat cancer.
Make it at home DIY!!
There are two basic steps in creating a ferrofluid: synthesis of the magnetic solid, magnetite (Fe3O4), and suspension in water with the aid of a surfactant.
A) magnetic ink developer (MICR) + veggie oil
(MICR contains iron oxide. Veggie as the solvent and source of surfactant, oleic acid)
B) Ferric chloride conversion
Fe3O4 can be prepared by a precipitation reaction that occurs upon mixing FeCl2 and FeCl3 with ammonium hydroxide.
The balanced equation for this reaction is as follows:
2FeCl3 + FeCl2 + 8 NH4OH⟶ Fe3O4 + 8 NH4Cl + 4 H2O
Check it out if you want more info:)
The following video tells you more about ferrofluid, please enjoy! :)