Unusual interactions between polymers explain hydrogel formation

Many people use hydrogels without knowing it. As superabsorbents in nappies, for example, hydrogels absorb a lot of liquid. In the process, the initially dry material becomes jelly-like, but it does not wet. Some people place the swellable material on their eyeballs—soft contact lenses are also just hydrogels. The same goes for jelly and other everyday materials.