Talk:Ferrofluid

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I think someone combined two sections that should not be together:

They are used in loudspeakers to sink heat between the voice coil and the magnet assembly, and to damp the movement of the cone. They reside in what would normally be the air gap around the voice coil, held in place by the speaker's magnet. Using electromagnets and sensors, the fluid's viscosity can be controlled dynamically. This allows hundreds of watts of mechanical power to be controlled with a few watts of electrical power, which is much more efficient than other methods of vibration control, such as piezoelectric crystals.

to my understanding, ferrofluid does not change viscosity under different magnetic fields, and is not used in that way to damp speakers. i think MR fluid is used to damp car shocks in that way, but it's not the same kind of damping. - Omegatron 02:49, Jul 8, 2004 (UTC)

Defn:

A ferrofluid is a stable colloidal suspension of ferromagnetic mono-domain particles in a liquid carrier. To avoid agglomeration due to attractive dipole-dipole or Van der Vaals forces each particle is coated by long-chain molecules or by an electrostatic layer (see figure). Due to the smallness of the particles (diameter ~ 10nm) the properties of ferrofluids are substantially affected by thermal Brownian motion. When exposed to a magnetic field, a ferrofluid behaves like a paramagnetic gas of high permeability (Rosensweig).

--Light current 07:58, 4 February 2006 (UTC)

Contents 1 Add 2 Take your pic 3 Copied 4 Diagram 5 How to section 6 Possible vandalism alert 7 Clarification needed 8 History 9 Idea 10 What if you Froze a ferrofluid whilst the magnet was present?

[edit] Add

Just added link to MRC page.

[edit] Take your pic

I have provided a number of images which I believe to be higher quality and more informative than the ones currently used on the article. Feel free to make use of them. --Gmaxwell 01:19, 13 July 2006 (UTC)

Whoa! — Omegatron 02:33, 13 July 2006 (UTC)

lets use all of them haha they are beautifulthuglas^T|C 20:48, 25 February 2007 (UTC)

[edit] Copied

Part of the article has been copied by [1] without respectng GFDL. Cruccone 23:37, 11 November 2006 (UTC)

I don't speak Slovak. Using Babel, I've asked a Wikipedian who does to speak to the author of the website. --Eyrian 23:52, 11 November 2006 (UTC)

[edit] Diagram

We need something like [2] [3] [4] [5] — Omegatron 05:35, 2 January 2007 (UTC)

[edit] How to section

Can I remove the tag? It's really not a big deal. — Omegatron 05:36, 2 January 2007 (UTC)

[edit] Possible vandalism alert

Slashdot recently linked to an article that prominently linked to this page on Wikipedia so keep your eye out for vandals. --froth^{T C} 07:43, 4 January 2007 (UTC)

[edit] Clarification needed

This is very confusing to me. First it is stated:

Ferrofluids are composed of nanoscale ferromagnetic particles

Later we read:

Ferrofluids have numerous optical applications due to their refractive properties; that is, each grain, a micromagnet, reflects light

When I link to the micromagnet hyperlink, I am taken to the article on magnets. So the second quote is saying that ferrofluids are composed of particles, each of which is a magnet. That is, each particle exhibits a magnetic moment (I guess is the way you say it) without an external magnetic field being applied. But if that is true, why is the first quote "Ferrofluids are composed of nanoscale ferromagnetic particles" and not "Ferrofluids are composed of nanoscale magnetic particles"? —The preceding unsigned comment was added by 4.238.240.56 (talk) 08:51, 18 February 2007 (UTC).

[edit] History

How/When/Why was Ferrofluid developed and by whom? Answer that question and this will be a better entry --CPQD 00:45, 25 February 2007 (UTC)

[edit] Idea

This is just an idea, but someone might want to increase the size of the pictures on the topic page, by a little bit.

Tell me if you want me to do it. --•Tbone55•^{(Talk) (Contribs) (UBX) (autographbook)} 20:44, 25 February 2007 (UTC)

I agree - its a nice image. Id do it but id probably delete wikipedia or something. I nominate you :P thuglas^T|C 20:46, 25 February 2007 (UTC)

[edit] What if you Froze a ferrofluid whilst the magnet was present?

Would this make the particles freeze in their new alignment? making the fluid a ferromagnet as long as it was frozen? I'd guess so, cos it would be like the heat and beat method of making iron ferromagnets. Does anyone know for sure? Tom Michael - Mostly Zen (talk) 22:39, 25 February 2007 (UTC)