Carbon dioxide as a solvent is well suited for use in textile operations such as scouring, dyeing and post-treatments because it can be used a solvent whose density (hence solvent properties) can be modified by simply changing the temperature and pressure of the carbon dioxide.  Carbon dioxide above its supercritical condition has the following attributes:

 

• scCO₂ is a solvent that can dissolve dyes, oils, surfactants, waxes etc.

• Solvent properties are tunable

• Behaves mostly like non-polar solvent e.g. alkanes (low dielectric constant and dipole moment)

• Has some quadrupolar characteristics; behaves like dioxane

• scCO₂ has some “Polar” attributes: Capable of weak Lewis acid and base interactions;
   Hydrogen bonding e.g. with amines; Fluorocarbon interactions

• Low cost

• Safe, environmentally benign/non-toxic,

• Readily recyclable

• Does not oxidize

• Pressure reduction converts to gas hence removal of scCO₂ as solvent does not require
   scCO₂ for Dyeing

• Conventional drying required to remove solvents such as water