A ferrofluid becomes strongly magnetized when placed in a magnetic field. This liquid is made up of very tiny (10 nanometers or less) particles coated with anti-clumping surfactants and then mixed with water (or solvents). These particles don’t “settle out” but rather remain suspended in the fluid.
The particles themselves are made up of either magnetite, hematite or iron-type substance.
Ferrofluids don’t stay magnetized when you remove the magnetic field, which makes them “super-paramagnets” rather than ferromagnets. Ferrofluids also lose their magnetic properties at and above their Curie temperature points.
Ferrofluids are what scientists call “colloidal suspensions”, which means that the substance has properties of both solid metal and liquid water (or oil), and it can change phase easily between the two. (We as show you this in the video below.) Because ferrofluids can change phases when a magnetic field is applied, you’ll find ferrofluids used as seals, lubricants, and many other engineering-related uses.
Here’s a video on toner cartridges and how to make your own homemade ferrofluid. It’s a bit longer than our usual video, but we thought you’d enjoy the extra content.
Please login or register to read the rest of this content.