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Ionizing solids- effects and materials

  1. May 31, 2013 #1

    taylaron

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    Greetings.

    I want to experiment with the effects of macroscopic ionized solids.
    But first, lets have a little 'thought experiment'!

    If I have say, a gram of elemental copper, surrounded by ultra-pure water and it's put into a device which is capable of filling all of the valence electrons in the copper atoms. The ultra-pure water would act as an electric insulator, preventing electrons from leaving the copper mass. The copper would be kept in the center of the water by magnetic levitation. Given the excess of electrons in the copper, it will have a very, very intense electric field.

    In this situation, is there a theoretical limit to the number of electrons one can inject into this mass of copper (after filling all the valence shells)? With sufficient water, the electrons shouldn't be able to leave, right? The copper would be very chemically unstable, but the water will prevent the electrons from migrating outwards, correct?

    Are there benefits to using different materials? Conductive or not? More or less valence shells? Will the electrons eventually creep out of the ultra-pure water environment? What are the big problems with this concept? Will the water actually react with the unstable copper?

    Thanks,
    -Tay
     
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  3. May 31, 2013 #2

    Simon Bridge

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    Hmm... copper is a conductor, so the valence band overlaps the conduction band.
    However I get that you want to put a very large charge on a lump of copper, and you want to keep them there with a very good insulator.

    If you keep piling in the charge, the insulator will break down.
    Electrons can fly off the conductor into the insulator ionizing it's atoms, burning holes in it, stuff like that.
    Basically, the model for electrodynamics you are using will break down.

    There are benefits to changing materials - there are better insulators than water and metals with a higher density of states than copper.

    Copper does not react with water normally, but the electric field would electrolyze the water.
     
  4. Jun 7, 2013 #3

    taylaron

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    Thanks for your feedback simon.
    Ive been looking at dielectrics and i thought that water was the best choice for breakdown voltage. Im puzzled how my model would breakdown if the dielectric is sufficiently thick.

    How would the water go through electrolosis if there is no current flow- provided the dielectric does its job...?
     
  5. Jun 7, 2013 #4

    Simon Bridge

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    Well you have used qualifiers like "sufficiently thick" and "provided the dielectric does it's job" which mean the answer is - it won't. Provided it is sufficiently thick and it does it's job.

    But that gets you nowhere - it does not tell you how thick, or under what conditions it will not do it's job.
    i.e. your question is under-specified.

    All real materials will break down at some voltage.
     
  6. Jun 8, 2013 #5

    taylaron

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    If i have a million volts with 1 mile of teflon insulation, im pretty sure the dielectric breakdown will not be the entire length of the teflon.
    But i think i understand what youre saying. The thickness of the dielectric is irrelevent when it comes to the breakdown of the marerial, correct? For some reason i thought current had to flow in order for a dielectric to break down. Am i right?
     
  7. Jun 8, 2013 #6

    Simon Bridge

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    do the math.

    I don't think so... I am saying that your statements are too vague to be any use.
     
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