Application of supercritical carbon dioxide for the processing of polymers in the form of nanofibers, textiles, films, foams, and aerogels

Abstract

Supercritical carbon dioxide (sc-CO2) has remarkable attributes as a processing medium such as high diffusivity, low viscosity, non-flammability, and inertness. In addition, it can be easily and completely separated from the final material, as well as fully recycled. This sets up sc-CO2-assisted technologies apart from conventional methodologies reliant on organic solvents. Some of the most prominent techniques that employ sc-CO2 are supercritical drying and supercritical impregnation for the functionalization of polymeric nanofibers, textiles, films, foams, and aerogels. Supercritical drying can be employed for the separation of liquids from wet polymer gels and the production of highly porous dry aerogels, while supercritical impregnation can be employed for the incorporation of bioactive components into polymer matrices. Overall, sc-CO2 technologies pioneer the development of next-generation materials while meticulous physical and chemical characterizations underpin the scientific journey.