Here Professor Martyn Poliakoff demonstrates supercritical fluids.

It was a demonstration like this which inspired his own interest in the area.

Supercritical fluids are used as alternative solvents, as Professor Poliakoff explains towards the end of this short interview.

I must apologise for the transition between gas and liquid in this film not looking as extraordinary as it does in real life - that's mainly due to the use of YouTube to encode the video!