Squeezing a sponge becomes cool
JAPAN: Researchers looking to replace HFCs in refrigeration systems claim to have achieved a liquid-to-gas phase transition using a sponge with small nanopores.
The team from Tohoku University, Nissan Motor Co, Shinshu University and Okayama University carried out a force-driven liquid-to-gas phase transition using a a sponge with a pore size of under 10 nanometres. Unlike with a conventional sponge, when applying force the expelled liquid immediately evaporates into gas. Furthermore, as the sponge returns to its natural shape, it adsorbs the gas as a liquid into the nanopores again.
Until now, researchers have not carried out the squeezing process of nanoporous materials because conventional materials are too hard to be deformed. Nevertheless, the team circumvented this by creating their own soft, elastic, nanoporous materials, consisting of a single-layer of graphene walls.
They are said to have measured their results using home-made equipment designed to monitor liquid-gas phase transition when mechanical force is applied.