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Conductivity of activated (porous) carbon

  1. Sep 24, 2009 #1

    taylaron

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    Hi, im doing an experiment involving activated carbon and I need to know if activated carbon has a high level of conductivity. i've searched the internet but without results. in addition, if the Active carbon can be made to be or is conductive, does the immense internal surface area still remain?

    Thanks everyone. I appreciate your input

    -Tay
     
  2. jcsd
  3. Dec 28, 2009 #2

    taylaron

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    Ok, perhaps a different question.

    I'm trying to find out how many coulombs of electricity I can store per m^2 on activated carbon. This is your classical question of "how much surface area in a capacitor does it take to equal the capacity of a battery?"

    I'm having difficulty because calculating the number of available valence electrons is difficult since all of the carbon atoms are bonded with each other, filling many of those valence electrons. I don't understand how one can mathematically calculate how many coulombs can be stored per square meter without knowing the exact molecular structure.
    Has there been an experiment done to provide this data?

    Regards,

    -Tay
     
  4. Dec 30, 2009 #3
    If I'm not mistaken, the molecular structure doesn't matter so much as the effective surface area of the material. In the case of a simple flat plate capacitor, the effective surface area is equivalent to the cross sectional area of material being used for the capacitor.

    And to answer your first question, yes carbon, activated or not, is very electrically conductive.
     
  5. Dec 31, 2009 #4

    taylaron

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    To my understanding, static electricity is the accumulation of electrons in the valence orbitals of an atom. I suppose if you took the mathematical average of the number of available valence shells per nanometer, one could calculate the exact number of coulombs that can be stored on a given amount of surface area. I was stuck with the concept that the varying molecular structure results in non-uniform bonds from atom to atom. The irregularity of these bonds would need to be known to calculate the number of valence shells to calculate the possible static electricity. The answer to my own question is to take the average number of valence electrons per unit surface area. If I am correct. One could take the measurement experimentally, but such high voltages have a tendency to leek through insulators, contributing to experimental error.

    In addition, I found that the answer to my question in that storing energy in the form of static electricity has significantly less energy density compared to possible chemical reactions. There are only so many valence electrons in an atom, but even more electrons can be transferred during a chemical reaction. This is the primary reason why super capacitors can (I want to say never) provide as much power in the long term than a battery.

    -Tay
     
  6. Feb 16, 2010 #5

    taylaron

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    Thoughts anybody?
     
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