In the early nineties of the last century, the film "Terminator-2" was released on the screens of cinemas. All the viewers were amazed by the ability of the gooey metal killer cyborg, played by Robert Patrick, to take on a variety of guises.
Then, admiring the professionally made computer animation, we did not think about the fact that the effect of fantastic transformations of a killer cyborg can be simulated in real conditions.
Ferrofluid is the material that allows you to see moving sculptural compositions. All substances can be attracted or repelled by a classical magnetic field. But the reaction of most of them is so weak that it can only be detected by special instruments. It would be great if it were possible to increase the magnetic properties of materials without destroying their structure and fundamentally changing their original properties.
Everything changed when chemists intervened and created ferromagnetic fluids with good fluidity. They managed to get the smallest magnetic particles that were introduced into liquids, and when exposed to a magnetic field, they did not clump and did not settle, but made the liquid "solid".
Ferrofluid is a colloidal dispersion of ferrites, ferromagnets with very small particles, stabilized in an aqueous or hydrocarbon medium, supported by surface-active substances. Such fluids are stable for several years and yet have good fluidity combined with magnetic properties.
Ferrofluid can be obtained in many ways. The process is quite simple and consists of two stages. First, it is necessary to obtain magnetic particles with sizes close to colloidal. And already further - to stabilize them in a liquid base.
The topic of the possibility of practical application of such liquids remains very relevant for researchers. In recent years, they have been working on the treatment of wastewater with such liquids from oil products. The principle of this process is the magnetization of oil products by introducing magnetic fluids into waste water. And then magnetized oil products are separated by special systems.
Ferrofluid will also find its application in medicine. For example, anticancer drugs harm he althy cells. But if you mix medicines with such a liquid and inject it into the patient's blood, and put it near the tumormagnet, the mixture will concentrate in the right place and will not damage the entire body.
Here's another example. Racing car companies fill their shock absorbers with ferrofluids. An electromagnet connected to them instantly makes the liquid viscous or fluid. Thus, the car's suspension is adjusted.
Such liquids also have curious properties. If a sound wave is passed through a magnetized liquid, then an electrical driving force arises in an inductive coil located nearby. And further. If you add magnetic fluid to the solution for soap bubbles, you will get a bewitching performance.