3. Principles of dense CO2 cleaning under pressure

3.1 Cleaning and surface treatment

We have seen that dense CO ₂ under pressure has good solvent power for apolar organic compounds. This is precisely what is encountered among industrial contaminants in film or particulate form. What's more, for more polar compounds, the addition of a co-solvent in small proportions makes it possible to maintain the supercritical phase while modifying the polarity of the solvent.

In many cleaning applications, contaminants are present in the form of inorganic particles. These adhere to the surface via strong electrostatic or capillary bonds. To remove these particles, it is necessary to penetrate the boundary layer and overcome the adhesive forces with a higher applied drag force....