Supercritical CO2 can be used as a solvent for in-situ chemical reactions.

Reference: Daniel Hermida-Merino, Giuseppe Portale, Peter Fields, Richard Wilson, Simon P. Bassett, James Jennings, Martin Dellar, Cedric Gommes, Steven M. Howdle, Benno C. M. Vrolijk, and Wim Bras; “A high pressure cell for supercritical CO2 on-line chemical reactions studied with x-ray techniques”; Review of Scientific Instruments, 85, 093905 (2014), DOI: http://dx.doi.org/10.1063/1.4895717

 

These photographs were taken in August 2012