Conducting polymer hydrogels

Conducting polymer hydrogels are gels, which are swollen with water, and contain a conducting polymer along with a supporting polymer as constituents. Polyaniline, polypyrrole or poly(3,4-ethylenedioxythiophene) represent the conducting moiety, while water-soluble polymers the other part. Various ways of hydrogel preparation are reviewed. The properties, such as mixed electronic and ionic conductivity, redox activity, and responsivity, are conveniently combined with materials properties afforded by supporting polymers, such as elasticity, mechanical integrity, and biocompatibility. The derived materials, aerogels obtained after freeze-drying of hydrogels, or carbogels produced after carbonization of aerogels, are also considered. The applications are expected especially in biomedicine and energy-storage devices but many other uses proposed in the literature are listed and discussed.