Some Polymer Geek Chic for the Weekend: Amazing Poly(acrylic acid)

No matter how often I see it demonstrated, I still think that poly(acrylic acid) and its salts are amazing materials. Sodium polyacrylate is used, as many of you know as a superabsorber – it can absorb about 1000 times its weight in water: 1 g is enough to turn a litre of water into a gel. Unsurprisingly, poly(sodium acrylate) is now a standard ingredient in baby diapers. It all works via hydrogen bonding…..the addition of salt to the gel will reverse the effect and destroy the gel: