Solvent Exchange: The liquid in the sample is exchanged with a solvent that has a low critical temperature and pressure, like carbon dioxide. Heating and Pressurization: The sample is then subjected to conditions where the solvent becomes supercritical, meaning it surpasses its critical temperature and critical pressure. Drying: Once the solvent is in its supercritical state, it can be vented off gently without causing capillary forces that can damage the nanostructure.
