Aluminium is unusual because it is a reactive metal that does not react with water. Its surface naturally forms a very thin layer of aluminium oxide that keeps water away from the metal below.

"These micelles act like tiny reaction vessels," said Ying Chen, first author of this study and a doctoral student in chemistry at Rice. "They enable chemical transformations that wouldn't normally ...

The first 'reaction' that we tried for our hand warmer involved dissolving potassium carbonate (K 2 CO 3) in water. Potassium carbonate is one of the chemicals left behind in the ashes of burnt wood.