Naked Science Forum
General Science => Question of the Week => Topic started by: Adam Murphy on 02/08/2018 10:34:28
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Martin asked us:
What’s the science behind non-stick pans? What prevents the sticking?
Any thoughts?
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One word: teflon. Teflon is an polymer, which does not like to bond with other chemicals. It looks like this: (https://upload.wikimedia.org/wikipedia/commons/e/eb/Perfluorodecyl-chain-from-xtal-Mercury-3D-balls.png)
The yellow thing is fluorine. It sticks to black balls-carbon-, so it does not stick to other atoms.
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We interviewed Ullrich Steiner about non-stick surfaces, superhydrophobicity and Teflon (https://www.thenakedscientists.com/articles/interviews/super-non-stick-surfaces) about 10 years ago.
He did an amazing demo in the studio with a spoon he's treated with the surface coating he had developed. He dropped a droplet of water onto the spoon, which was held at an angle and the water literally leapt off. I remember it vividly to this day!
You can listen to the interview here: https://www.thenakedscientists.com/sites/default/files/media/Naked_Scientists_Show_07.09.30_423_1.mp3
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This question has now been answered! You can listen to it here: https://www.thenakedscientists.com/podcasts/question-week/how-do-non-stick-pans-work
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On a related note, one interesting thing I found in my travels- linoleum (polymerised linoleic fatty acids) can approach the slipperiness of PTFE but only when wet or oiled. I think that's why chefs often 'prove' pans- it polymerises the oils and forms a very slippery linoleum-like layer:
https://physics.info/friction/
(Note flooring called 'linoleum' these days is nearly always actually PVC, specifically because linoleum is too slippery when wet.)
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One word: teflon. Teflon is an polymer, which does not like to bond with other chemicals. It looks like this: (https://upload.wikimedia.org/wikipedia/commons/e/eb/Perfluorodecyl-chain-from-xtal-Mercury-3D-balls.png)
The yellow thing is fluorine. It sticks to black balls-carbon-, so it does not stick to other atoms.
So, if we put a food which contains carbon, like a burnt chicken, it will stick?
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There have been health concerns raised about much shorter-chain fluorinated carbon molecules.
Some of these have been used in airports for flame-retardent sprays for avgas fires, resulting in high levels of exposure by firemen. The water-soluble end to the chain would make it more dangerous to living organisms.
See: https://en.wikipedia.org/wiki/Perfluorooctanesulfonic_acid
https://en.wikipedia.org/wiki/Perfluorooctanoic_acid
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Due to Teflon coating.