Ferrofluid- CTS Part 2b

Someone may find it hard to know what ferrofluid is, even though it was, too often, used in the previous posts by me and Caryn Chang, as a part of our CTS tasks. I, for one, was confused over it and yummy Ferrero Rocher.I was thinking, ferrofluid - could it be a type of chocoliquid used to produce real Italian hallmark chocolates like Ferrero Rocher?

Cut the chatter.My apologies for my randomness.


Ferrofluid is a liquid which becomes strongly polarised in the presence of a magnetic field. The word is derived from the Latin word ferrum, meaning iron, and the word fluid. Ferrofluids are colloidal mixtures which is consisted of nanoscale ferromagnetic, or ferrimagnetic, particles suspended in a carrier fluid, usually an organic solvent or water. The ferromagnetic nano-particles are coated with a surfactant to prevent their agglomeration or the process of breaking down (due to van der Waals forces between particles and magnetic forces). Although the name may suggest otherwise, ferrofluids do not display ferromagnetism, since they do not retain magnetization in the absence of an externally applied field, which in the case of Morpho Towers, electromagnestism. In fact, ferrofluids display (bulk-scale) paramagnetism, and are often described as "superparamagnetic" due to their large magnetic susceptibility. Permanently magnetized fluids are difficult to create at present which is why the ferrofluid of Morpho Towers only react when the electromagnet is magnetised and the music turned on.


The surfactants used to coat the nanoparticles, as mentioned above, include, but are not limited to:

(i) oleic acid


(ii) tetramethylammonium hydroxide


(iii) citric acid


(iv) soy lecithin

As envisaged by Sachiko Kodama, ferrofluid can also be incorporated to the construction of sculptures, buildings or structures. However, the range of usage of ferrofluid is nevertheless wide currently. Ferrofluid is applied in manufacturing electronic devices, of which the most common is hard disks. Ferrofluids are used to form liquid seals around the spinning drive shafts in hard disks. The rotating shaft is surrounded by magnets. A small amount of ferrofluid, placed in the gap between the magnet and the shaft, will be held in place by its attraction to the magnet. The fluid of magnetic particles forms a barrier which prevents debris from entering the interior of the hard drive.

Besides, ferrofluids are used in mechanical engineering. With friction-reducing capabilities, ferrofluid is applied to the surface of a strong enough magnet, such as one made of neodymium, so that the magnet can glide across smooth surfaces with minimal resistance.

Other fields incorporating the use of ferrofluids:

- Military
- Aerospace

- Analytical Instumentation

- Heat Transfer

- Medicine

- Optics

and...

Of course, Arts, by Sachiko Kodama, whose idea could be incorporated in buildings and construction.

So, BASICALLY, this is a basic introduction of Ferrofluid, which is interesting enough to be explored on.

As promised.

`Ng Loon Jay, Jasper'
17 February 2010

Source: wikipedia, with slight modification.