Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: DaddyB on 25/12/2012 03:48:55
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I was trying to create a 3d visible magnetic field from ferrous metal shavings in a glass jar suspended in otc clear liquid dish soap. I was hoping to be able to create full loops that would stay suspended for a short time or long time for viewing. I conducted it on a small scale first to find out if small dust and shavings would work instead of making or buying larger ones from a scientific web store. The shavings were from common nuts and bolts ground with a pedestal grinder.
I mixed the shavings and soap in the jar and allowed them to settle overnight to see how fast they would fall in the soap, to check viscosity, then mixed it again and put a common cheap rectangular hardware store magnet under the jar overnight.
In the morning, I did not have the full loops I had hoped for but instead had a nice 3d group of spires formed around the expected common magnetic field, minus the loops.
Fine. I'll need to try different size and shape metal bits and probably a stronger magnet, which I have.
Here's where it gets weird.
There is microscopic bubbles slowly rising up from the bottom of the jar and the magnetic field spires, for the last few days, non-stop. I steady and easily visible wall of them, rising, along the length axis of the magnet below, and reasonably straight up to the surface of the soap.
And the weirder part is, the wall of bubbles seen from the side, is wide at the bottom narrow in the middle, and wide at the top of the soap surface.
What is going on here?
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... microscopic bubbles slowly rising up from the bottom of the jar and the magnetic field spires, for the last few days, non-stop.
Bubbles of Hydrogen* gas can be created when iron rusts ... http://corrosion-doctors.org/Experiments/rust-chemistry.htm
The apparatus you are replicating uses mineral-oil not liquid-soap, (which contains water, enabling rusting).
Apparently baby-oil will do ... http://www.darylscience.com/Demos/3DMag.html
The liquid isn't absolutely necessary ...
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fcse.ssl.berkeley.edu%2Fsegwayed%2Flessons%2Fexploring_magnetism%2FExploring_Magnetism%2FExploring_Magnetism_images%2FExploring_Magnetism_img_4.jpg&hash=3efa37118df73ea1f4c838fba2f746ed)
http://cse.ssl.berkeley.edu/segwayed/lessons/exploring_magnetism/Exploring_Magnetism/s1.html#act2
[ * Alternatively the fine iron particles are providing nucleation sites for air dissolved in the liquid soap ... https://en.wikipedia.org/wiki/Nucleation ]
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Two things to note:
1. When I have seen this done before, glycerin was used-very distinguishable loops were visible (just another medium to try)
2. To stop producing spires and start producing loops, you may need to add more iron shavings (note how the shavings didn't form loops on the outside near the poles in the pics RD posted)
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Keep my last post in mind, but I just realized what is actually wrong. A magnet's magnetic field forms a loop from the north to the south pole, not north to north and south to south. You need to suspend your magnets in the liquid, or use two magnets.