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Iodine povidone is a complex of iodine and the polymer povidone. I am wondering if one were to heat it enough, the iodine would sublimate and could be collected. Normally iodine boils at 184.3 °C, according to wikipedia.

A video of how the procedure might work, except iodine crystals would replaced with boiled down iodine povidone: Sublimation of Iodine Time lapse

This can be used to purify iodine, so from my understanding, you would be able to vaporize the iodine and leave the polymer behind.

Does the complex with povidone change how this would work?

I apologize if my question is ignorant, as I do not have a great understanding of how complexes work.

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2 Answers 2

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Yes you can because it is in a complex with the povidone. You just have to heat it a little bit extra. This is because a complex is "tangled up" molecules. In this case it is Povidone and Iodine. Nile Red used a different process (liquid-liquid extraction), but here is the link. https://www.youtube.com/watch?v=FNf8PSda7iI

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  • $\begingroup$ Yes, I've seen Nile Red's video. Since he removed most of the polymer through his process, I was not sure if you could merely sublimate the iodine out. Any idea if what kind of heat you might need to do so? $\endgroup$
    – ChemBird
    Commented May 20, 2016 at 21:50
  • $\begingroup$ Would about ~200 C be enough? $\endgroup$
    – ChemBird
    Commented May 20, 2016 at 22:20
  • $\begingroup$ Should be. Experiment around $\endgroup$ Commented May 21, 2016 at 14:16
  • $\begingroup$ 150-180 C is when Povidone Melts $\endgroup$ Commented May 21, 2016 at 14:18
  • $\begingroup$ As long as your povidone doesn't evaporate/boil your experiments should go fine $\endgroup$ Commented May 25, 2016 at 12:24
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A procedure is available on Erowid for this process.

Make or buy a coldfinger (see below), boil your fluid to absolute dryness, without burning the dry restant, then hang your coldfinger in an appropriate Erlenmeyer, and heat gently the now dry restant. Make your coldfinger fat-free with acetone first (on the outside where the I2 will condense). The I2 will sublimate from the solid form into the gas form, without getting a fluid first (that's sublimation), and the gaseous I2 will resublime from the gaseous form into the solid form against the cold wall from the coldfinger. A little bit will of course also resublime against the upper part of the Erlenmeyer, but that you can also scrape off later, when all your 10% I2 hangs on the cold glass walls.

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