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Magnetic liquid

  1. Apr 2, 2015 #1

    Is there any liquid available that is magnetic at room temprature? I know that liquid helium is magnetic but at very low tempratures not at room temperature.

  2. jcsd
  3. Apr 2, 2015 #2


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    Ferrofluids? http://en.wikipedia.org/wiki/Ferrofluid

  4. Apr 3, 2015 #3
    Ferrofluid does not retain its magnetic effect. It is affected only when a magnet is close to it, I meant is there a sort of fluid that is permanent magnet not temporary. But thanks for the reply
  5. Apr 3, 2015 #4


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    I think it is more abut physics than about chemistry.

    Somehow I doubt it is possible at all. Solid magnets contain ordered magnetic domains, in liquid they will immediately reorder to have the lowest energy possible, that would mean most of local fields canceled out and no stable field outside.

    I will move the thread to physics.
  6. Oct 21, 2015 #5
    You can make your own ferrofluid (note the name... ferrofluid... because it's ferromagnetic). Buy some 25 nanometer iron particles (from Sigma Aldrich or similar), mix them in with a clear viscous oil, and you've got your ferrofluid. You'll have to experiment with oil viscosity and amount of iron particles to get the ferrofluid you want.

    One interesting application of ferrofluid is a ferrocell:
    1) Take two thick pieces of glass or Lexan or similar.

    2) Roll a very thin film of ferrofluid on one side of each of the glass pieces.

    3) Compress the two glass pieces together (ferrofluid sides together) firmly and evenly while rotating them to disperse the ferrofluid evenly and squish out any excess.

    4) Clean up any ferrofluid that squished out.

    5) Seal up the perimeter of the two pieces of stacked glass with silicone caulk.

    6) Rig up red, green and blue LEDs around the perimeter of each piece of glass (not at the outside so the light shines through the caulk, on each outer side of the glass.
    You'll have to make your blue LEDs slightly brighter than your reds and greens, because the glass tends to attenuate blue light. Aim for as white a composite light as you can get.

    7) Turn on the LEDs and place a magnet under the glass pieces while viewing it from the opposite side. You'll be able to actually see the magnetic lines of flux in real-time and 3-D, in color (ie: you'll see the red and blue colors diverge).

    8) For an even more magnificent 3-D view, stack three or four glass panes together, with ferrorfluid between each. You'll have to ensure your ferrofluid isn't too dark, and you'll double or triple the number of LEDs used, but it's a mind-blowing look at the inner workings of magnets.

    You can also use nanometer ferric borate (FeBO3) crystals (they're transparent) and an oil with a slight color to it (or different colors (RGB) for each layer of a multi-layer ferrocell). The nanometer ferric borate is harder to find, though. But it does away with the brown color of traditional ferrofluid.
    Last edited: Oct 21, 2015
  7. Oct 21, 2015 #6

    Andy Resnick

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    Whoa... I'm making one ASAP. Thanks!
  8. Oct 21, 2015 #7
    Ferrocell USA makes some good ones, but they're small and only two-paned. You can use whatever size and however many glass pieces you like if you build it yourself. One that's double the size of a commercial unit, with ultrabright LEDs and three panes, gives an astonishing view.
  9. Oct 21, 2015 #8
    I forgot to mention, you can use black toner in place of iron particles. But it makes a very black liquid. You'd have to experiment with the amount of toner to get a really light greyish color that the LEDs can shine through. It's best if you start with oil that's as close to optically clear as possible.

    I've not experimented with color toner, so I don't know what qualities (if any) it'd have in a multi-pane ferrocell.
  10. Oct 23, 2015 #9

    Andy Resnick

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    I assembled a few test cells using a glass slide, coverslip and about 5 uL of ferrofluid and have been playing around with them- very cool, thanks for the tip!

    Still working on how to get a magnet close enough while still able to image with a microscope, I've had some success but I'm not quite ready to trash a mirror just to enable epi-illumination.
  11. Oct 8, 2016 #10
    Not trying to be obtuse here, but if you follow ScooterGuy's instructions for making a 'Ferrocell', you will be sadly disappointed. There is no way you can 'spread the fluid' without getting bubbles everywhere. I've made these cells easily affordable over time and I think you will be surprised how cheap a complete viewing system can cost. This isn't my attempt at selling anything, just a FYI for those of you who take the advice of someone who has never actually made a functioning, imitation Ferrocell. Where are his pix? Does he get images like this: http://www.ferrocell.us/experiments.html
    And in many cases, I supply students, college and university labs with FREE cells for test and evaluation. All I ask is to be 'kept in the loop' with their research.
  12. Oct 8, 2016 #11
    I understand that you have to protect your business of selling FerroCells, but don't do it by bashing someone else, PineStone. I stated that you make good ferrocells, but they are small and only two-paned. If one is working with smaller magnets, yours work great. If one is working with larger magnets and they want a full view of the field, they're forced to build their own.

    As an open-source experimenter, you should be encouraging others to build their own... they might come up with something you can then incorporate and sell... not everyone is going to build their own, and those who will build their own likely won't buy one... either way you lose nothing and potentially gain. Three things I was looking for were more durability so any contact with the magnet didn't chip or break the glass, a larger view, and a deeper, more "3-D" view.

    As for the "getting bubbles everywhere", that's the reason for putting the two panes together as you rotate them... it squeezes the air outward. One can also lightly and evenly clamp the two panes together, and slowly "inject" the ferrofluid between the panes, allowing capillary action to draw the fluid in. As the fluid spreads from the single injection point, it'll force the air out until the fluid reaches the lip of the two panes all the way round.
  13. Oct 9, 2016 #12
    I had no intent of 'bashing' anyone, especially you. I admire anyone who can look at something and re-create it. My concern is you are giving out information that may be flawed. If you had really made cells using your technique, you would have also warned people how extremely messy this construction technique can be.
    Squeezing out the excess will get that black, staining fluid EVERYWHERE !!!
    And, since you didn't post any pix of your 'homemade' cells or the images they are capable of producing, I will assume you didn't actually make one.
    Silicon sealer? If you used silicon, you would see how the fluid 'leaks' through it, even after it dries. I found this out early during my development stage (2005).
    For all of you experimenters out there who want to make your own cells, I suggest you use two coats of optical adhesive (UV cured).
    The first layer should be Nortel #81 and the second layer #63. They won't leak if done properly.
    How small is 'small'? is 100mm to tiny for you to work with? That's the size of my most popular Ferrocell.
    And yes, this is a business for me. I've spent many many thousands of dollars during the patent and development stages to assure people of an affordable, high quality product that will give years of use without issue. All I'm trying to do is 're-cap' some of my expenses. Like I said earlier, I've given away many Ferrocells in an effort to help students and universities. Its not all about the money.
    I'm an old guy and not long for this world (died last year, but they brought me back). I have a deal with my wife- she's going to post my 'how to' videos on YouTube after I'm gone for good. Then people can see for themselves how to make quality cells.
  14. Oct 11, 2016 #13
    As for your "black, staining fluid EVERYWHERE !!!", that wasn't your first argument against my recommendations, PineStone, so you're waffling now in defense.

    Of course it'll be messy, it's a dark fluid. Does one need a warning that changing their engine oil could be messy? If so, they shouldn't be changing their engine oil. LOL

    I've not experienced any leakage using silicone, but then I used oil-impermeable silicone regularly used for engine gaskets, perhaps I will in the future, but then I can just either reseal it, or take your recommendations to use Nortel.

    Yes, 100 mm is too small for some. Do you realize the size of some of the available magnets? And that's not taking into consideration someone who builds their own large Halbach array, which is what I'm trying to do.

    As for posting pictures... what's the point? There are tons of pictures out there of ferrocells, one or two more won't make a difference. Especially for what I'm using it for, to get a whole-field view of an array.
  15. Oct 11, 2016 #14
    You see my warning and concern as a defensive move. Not what I intended by that statement. If you use the right tools and techniques, changing your engine oil is not a messy job at all. Squishing out a few ml of ferrofluid is probably the most messy situation one could ever encounter. A warning would have been appropriate.
    I have no issues with you duplicating a Ferrocell for personal use and I encourage anyone with the abilities and determination to do so.
    My main comments are:
    1) Be careful with this fluid- it stains, gets into every tiny pore and crevice and takes a long time to clean up.
    2) I doubt your method of building a cell will result in a useful tool.
    3) I'm calling you out on your actual building of a cell using this technique of yours by requesting a photo of your finished unit be posted for all to see. Talk is cheap.

    Science is all about the experiment (unless you are into theoretical physics).
    A photo of your Halbach array under the cell would be very educational for everyone to see and prove your experiment is what you say it is.
  16. Oct 11, 2016 #15


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    @pinestone has valid comments,

    but as said, we want to see pic's of YOUR cells.
    Seeing some one else's cells doesn't prove that your experiments have been fruitful :smile:

    Last edited: Oct 11, 2016
  17. Oct 11, 2016 #16

    Andy Resnick

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    Whoa... necro thread alert. For my part, the ferrocell assembled fairly easily (no bubbles, no leaks), and while I couldn't see field lines, I watched the particle chains move around for the better part of an day before I had to get back to work. I sealed the edges with nail polish, and 1 year (!) later, it's still sealed. I'm not going to bother posting a pic.
  18. Oct 11, 2016 #17
    You could have done that with a small bottle of ferrofluid and a magnet. But I'm glad you didn't end up with a mess or wasted fluid everywhere.
    Nail polish, really? I'm impressed.
    I agree, why bother to post a pix of something that didn't work...
  19. Oct 11, 2016 #18


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    This is going nowhere, thread locked.

    Edit: if anyone wants to post pictures, please contact me directly.
    Last edited: Oct 12, 2016
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