Supercritical fluid (SCF) is defined as "non-compressible and high density fluid". The
temperarure and pressure are higher than critical temperature (Tc) and critical pressure (Pc)
they are proper to fluids. SCF has high thermal motion, and it is possible to change the density
widely (from low like a gas to high like a liquid), therefore we can control many properties whose
function is expressed by density. Comparing the liquid, SCF's properties are greatly influenced
on the slight pressure change, in other words, it is possible to control the properties as solvent
just using one fluid.
