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Unexpected light from some reactions

  1. Jul 27, 2012 #1
    dear all,
    in a series of experiments on the interaction between sodium hydroxide and other molecules such as water, Triton X-100, formaldehyde and others, we found emission of light. Besides the formaldehyde-NaOH interaction, i.e. the Cannizzaro reaction in which some intermediates may form undergoing highly energetic transitions, we have no useful ideas of the mechanism reponsible for such light emission. Our equipment is insensitive to thermophotons, so the exothermicity of the above reactions as the primary source of measurable photons should not be directly involved. Aiming to go more in depth into the aforementioned phenomenon, please consider this post a call for suggestions and/or partnership.
    thanks,
    Leopoldo Silvestroni
     
  2. jcsd
  3. Jul 27, 2012 #2

    jedishrfu

    Staff: Mentor

    could you use a spectrometer to determine their frequencies and thereby what series they might belong to baumann. lyman...? Maybe that would help determine the chemical bond that was creating the light.
     
  4. Jul 27, 2012 #3
    I don't know much about physical chemistry. What is the baumann series? Do you mean Balmer series?
     
  5. Jul 27, 2012 #4
    Roughly, emitted light is in the green-blue region, as assessed by a photomultiplier tube close to the reaction vessel with (broad band) thin plastic filters in between
     
  6. Jul 27, 2012 #5
    Have you tried removing substances to see if you get the same behavior with fewer reactants?
     
  7. Jul 27, 2012 #6
    yes. water-NaOH, water-TritonX100, formaldehyde-NaOH are some examples. Light was produced in all the above reactions, though with different intensities (photons per sec)
     
  8. Jul 27, 2012 #7
    Is the total light intensity equal to the sum of the intensities from the individual reactions? I'm assuming these are exothermic reactions? If so, could this be due to increased radiation (blackbody) from the increase in temperature?
     
  9. Jul 27, 2012 #8

    chemisttree

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    I assume that all of these experiments were conducted in absolute darkness?
     
  10. Jul 28, 2012 #9

    jedishrfu

    Staff: Mentor

    Yes balmer series, my bad memory, sorry.
     
  11. Jul 28, 2012 #10
    I'm referring to individual reactions only. The "simplest" example is dropping water onto solid NaOH. Which excited intermediates relaxe with photon emission in our spectral window? (our photomultiplier tube has a 330-550nm spectral sensitivity).
    Note: when potassium hydroxide or barium hydroxide are substituted for NaOH, NO light is produced.
    Light emission comparable to the above also occurs in the more complex and intermediate-rich formaldheyde-NaOH reaction (i.e. Cannizzaro's reaction).
    Moreover, light emission is also produced upon mixing hypochloride and sodium ascorbate solutions, a reaction occurring without apparent heat production.
     
  12. Jul 28, 2012 #11
    Ground signal from our apparatus is always below 30-50 photons per sec. The cited reactions give a photon output of even dozens of thousands of photons
     
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