Materials processing in supercritical carbon dioxide: surfactants, polymers and biomaterials

Supercritical carbon dioxide (scCO(2)) is a unique solvent with a wide range of interesting properties. This review focuses upon recent advances in the use of scCO(2) in materials synthesis and materials processing. In particular, we consider the advances made in three major areas. First the design and application of new surfactants for use in scCO(2), which enable the production of metal nanoparticles, porous polymers and polymers of high molecular weight with excellent morphology. Second the development of new polymer processing and polymer blend technologies in scCO2, which enable the synthesis of some very complex polymer composites and blends. Finally, the application of scCO(2) in the preparation of novel biomedical materials, for example biodegradable polymer particles and scaffolds. The examples described here highlight that scCO(2) allows facile synthesis and processing of materials, leading to new products with properties that would otherwise be very difficult to achieve.