How does current in an electrolyte influence the flow of the liquid?

Discussion in 'Physics' started by Erty, Nov 12, 2014.

  1. Erty

    Thread Starter New Member

    Aug 9, 2010
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    In general, an electric current is a flow of charge. In an electrolyte it is a flow of ions. But how does this electric flow influence the overall flow of the liquid?
    I have already seen how it influences plasmas and how it makes the plasma react to external magnetic fields, and I'm curious about what it does to liquid electrolytes. Would it be correct to assume it shows similar effects but only a lot weaker due to lower conductivity and higher flow resistance from viscosity?
     
  2. Wendy

    Moderator

    Mar 24, 2008
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    You want to try an interesting experiment, add corn starch to water to make a almost thick gruel.

    The insert two electrodes, two metal bars, dinnerware, whatever. When they are energized with a 1 1/2 volt battery the liquid becomes very thick, when the current is removed it runs right off the electrodes.

    Starch polymerizes in the presence of current, and goes random with no current. The water is not really involved (I think), it is a function of the starch in water.
     
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  3. alfacliff

    Well-Known Member

    Dec 13, 2013
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    current through water in a magnetic field can make it move due to lorentz forces. the act of passing current through water creates a magnetic field, and can make the water move.
     
  4. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    You may want to look up, "electroendosmotic flow" or just electroendosmosis (http://en.wikipedia.org/wiki/Electro-osmosis ).

    It is a very real and potentially useful phenomenon that can aid separation of particles (e.g., bacteria), proteins, and solutes. Even solutes that are not charged can be separated by electrophoresis because of movement caused by electroendomosis.

    As to the effect of magnetism, there are some ancient (circa 1960's) studies of using a magnetic field to stabilize electrophoresis in liquid, non-gel media. Today, we use mostly capillary electrophoresis to accomplish the same or greater speed of separation.

    John
     
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  5. studiot

    AAC Fanatic!

    Nov 9, 2007
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    Never come across that one, Bill.

    It's nice to learn something every day.

    I also thought jpanhalt's summary a good one.
    Please add magnetohydrodynamics (MHD) and electrohydrodynamics (EHD) to John's list of long technical words.
    Google has both.

    Erty, what sor of current are you thinking of?

    An impressed current from an external supply or a current due to the ions within a battery that is supplying current?
     
    Last edited: Nov 12, 2014
  6. Erty

    Thread Starter New Member

    Aug 9, 2010
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    I was mostly just curious about the whole subject of physical effects on an electrolyte carrying a current since this has been a field both I and my teachers had completely overlooked when I was learning about electricity, with the exception of effects such as joule heating and electrolysis. I would probably been kept unaware of this subject if I had not skimmed the Wikipedia article about magnetohydrodynamics which stated it applies to electrolytes as well.
     
  7. studiot

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    Oxidation and Reduction chemical reactions involve the transfer of electrons. Those that occur in solution (such as rusting) pass an electric current.
     
  8. alfacliff

    Well-Known Member

    Dec 13, 2013
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    and motion due to convection currents from heating. motion due to gas bubbles forming during rapid charge/discharge.
     
  9. wayneh

    Expert

    Sep 9, 2010
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    The magnetohydrodynamic pump demonstrations on Youtube are fun. This one is very simple and nice.
     
  10. alfacliff

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    Dec 13, 2013
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    also, there is a bit of info about "electric propulsion" for boats on the internet.
     
  11. BR-549

    Well-Known Member

    Sep 22, 2013
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    "In an electrolyte it is a flow of ions." Are you sure?

    "But how does this electric flow influence the overall flow of the liquid?" Many variables.

    "I have already seen how it influences plasmas and how it makes the plasma react to external magnetic fields." Please tell me in what way does current influence plasma?

    Your question about charge flow can not be answered with current science. There is still much debate about how current flows.

    Many people will tell you that current has been well studied and understood. And like I, you can spend many days and read many studies and come out thinking you know how current flows. Not to mention working with it all your life.

    And then along comes Ferro fluids. I suggest that you u-tube it. Watch many.

    With the slightest movement......a magnetic field always twists. Even when it is static....it has a geometrical twist to it. With all the studies on conductor current, drift current, etc.......There is no mention of twist. Yet current has been well studied and verified. Don't be a current denier.

    They are probably working on their skin effect equations now. I have even heard this described as a quantum effect.

    I wouldn't discount electron flow in an electrolyte. And there should be a twisting or spiraling magnetic field between electrodes.

    Even in a DC conductor....the magnetic field is perpendicular........but it spirals and moves....The magnetic field is not rings around the conductor.....it is spirals.

    There are many scientific theories today that have been well studied and verified. None has been more studied and used than electronics and electricity. Yet for 100 years we still question current.

    Why? Because we don't have a clue of what matter is.
     
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