A conductive polyaniline (PAN) film was successfully synthesized in a homogeneous supercritical carbon dioxide (scCO2)/acetonitrile (AN) system. The homogeneous supercritical state was confirmed by observations of the phase behavior of the system through a high-pressure cell with a viewing window. The flatness of the film in that system decreased with the further addition Of CO2. This result suggests that the low viscosity Of ScCO2 plays an important role in improving the transfer rate of solvent. The roughness of the film prepared in the homogeneous ScCO2/AN system was reduced compared with that of the film prepared in dichloromethane itself as a solvent. The slow growth of the film and the high diffusion rate of the monomer seemed to account for the smooth and flat film formation.
- Supercritical carbon dioxide