Ultralight conducting polymer/carbon nanotube composite aerogels

By embedding carbon nanotubes into poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) (PEDOT-PSS) supermolecular hydrogels in the presence of a very small amount of polyvinyl alcohol (PVA), we have presented the fabrication of ultralight conducting polymer/carbon nanotube composite aerogels with the apparent density of 0.04-0.07 g/cm³ made by supercritical CO ₂ drying of as-made composite hydrogel precursors. The carbon nanotubes employed here are directly applicable to pristine (MWCNTs) or acid treated (c-MWCNTs) multi-wall nanotubes. Infra-red spectroscopy is used to confirm that PVA used for stabilizing nanotubes during the synthesis of hydrogel precursors has been completely removed by solvent exchange before supercritical CO₂ drying. The morphology and textural properties of the resultant composite aerogels are investigated by scanning electron microscopy, nitrogen adsorption/desorption, and X-ray powder diffraction tests. The thermal stability, together with electrical conductivities, of the resulting composite aerogels is revealed by the thermal gravitational analysis as well as conductivity tests. The results show that embedding of either MWCNTs or c-MWCNTs into PEDOT-PSS aerogel matrix can significantly enhance the specific surface areas (280-400 m²/g), the thermal stability and electrical conductivities (1.2-6.9 × 10^-2 S/cm) of the resulting composite aerogels.