Conducting polymer aerogels from supercritical CO₂ drying PEDOT-PSS hydrogels

The organic conducting PEDOT-PSS aerogels can be prepared by supercritical CO₂ drying of metal ion crosslinked PEDOT-PSS supermolecular hydrogels. The PEDOT-PSS hydrogel precursors were synthesized by polymerizing 3,4-ethylenedioxythiophene with excess ferric nitrate as oxidizing agent as well as crosslinking agent in the presence of poly(sodium 4-styrenesulfonate). The supermolecular crosslinking mechanism of the hydrogel precursors and the chemical composition of the resulting aerogels were revealed by X-ray photoelectron spectroscopy (XPS). The molecular structure of the resulting PEDOT-PSS aerogels was further confirmed by Raman and infra-red spectroscopy. The morphology and textural properties of the resultant aerogels were investigated by scanning electron microscopy (SEM), nitrogen adsorption/desorption, and X-ray powder diffraction (XRD) tests, respectively. The resulting aerogels show light weight (0.138-0.232 g cm^-3), large BET surface area (170-370 m² g^-1) and hierarchically porous structure with wide pore size distribution. The large surface area and wide pore size distribution, together with their electro-optical properties, would allow these organic conducting aerogels to be applied in many fields with unexpected performance.