Nappies are a very useful product for everyone involved: dads, mums and the babies themselves! Modern nappies use a substance known as a super slurper, which was invented by chemists to absorb lots of pee.
Take a baby’s nappy and cut out part of the pee-absorbing area. Remove the filling.
Push the filling from the nappy into the empty drinking glass, until the glass is half-full.
Gradually add small amounts of water to the half-filled drinking glass. How much water can the filling absorb?
What did you discover
If you look closely at the filling, you see that a kind of gel has formed. This is because the filling in babies’ nappies has one very important property – it can hold a lot of moisture. And that’s exactly what we need a nappy to do.
As it bonds with all that water, the structure of the nappy material changes quite a bit – which is why it looks like a gel. The gel can hold so much liquid that some super slurpers can consist almost completely (99%) of water!