Scientists say that soot is superhydrophobic
What happens when you cover an egg in soot? It gets super black, but also super shiny!
Safety: To do this activity, you will need to put your hands near a candle flame. Make sure you have an adult to help.
First aid: If you burn your hand, run it under cold water for 20 minutes. If needed, seek medical advice.
Soot is amazing stuff. It’s made of tiny particles of carbon, and it really doesn’t like to stick to water. Scientists say that it’s superhydrophobic, which roughly translates to ‘super scared of water’.
When you put a sooty egg into water, a very thin layer of air is trapped between the soot and the water. It’s light reflecting off that layer of air that makes the egg look shiny. When you take the egg out, it might still be dry!
So how tiny are these particles of soot? Scans show soot particles can be less than a millionth of a centimetre wide. On your egg, there could be trillions and trillions of soot particles, stacked together in complex shapes. This black coating is a carbon nanomaterial!
Scientists are researching soot coatings because they are superhydrophobic and yet cheap and easy to make. Soot layers might one day be used stop ice building up on aircraft wings and power lines, or to stop barnacles and algae from growing on the bottom of ships!
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10 September, 2020 at 1:56 pm
I’ve tried this experiment before expecting it not to work ut to my surprise it works so well.
10 September, 2020 at 1:57 pm
Yup! it took me a couple of goes to get it to work well, but with enough soot, it’s really amazing – looks even better than the pictures!