Materials processing in supercritical carbon dioxide: surfactants, polymers and biomaterialsElectronic supplementary information (ESI) available: video clips relating to work carried out in the Howdle research group. See http://www.rsc.org/suppdata/jm/b3/b315262f/

TLDR

Supercritical CO₂ is a unique solvent with versatile properties. The review surveys recent advances in using scCO₂ for materials synthesis and processing. It examines three key areas: surfactant design for nanoparticles and polymers, polymer processing and blend technologies for complex composites, and scCO₂ applications in biomedical materials such as biodegradable particles and scaffolds. These examples show that scCO₂ enables facile synthesis and processing, producing materials with otherwise hard‑to‑achieve properties.

Abstract

Supercritical carbon dioxide (scCO2) is a unique solvent with a wide range of interesting properties. This review focuses upon recent advances in the use of scCO2 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 scCO2, 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 scCO2 in the preparation of novel biomedical materials, for example biodegradable polymer particles and scaffolds. The examples described here highlight that scCO2 allows facile synthesis and processing of materials, leading to new products with properties that would otherwise be very difficult to achieve.