Nanoparticles of conductive polypyrrole (PPy) and its derivatives such as 3-heptylpyrrole (HPy) were successfully synthesized in a homogeneous supercritical carbon dioxide (scCO2). The homogeneous supercritical state was confirmed by observations of the phase behavior of the system through a high-pressure cell with a viewing window. Therefore, it became possible to synthesize their nanoparticles without the use of an organic solvent. The size of nanoparticles in the system decreased with more addition of CO2. This result suggested that the density of CO2 plays an important role in the control of the particle size.
- Poly (3-heptylpyrrole)
- Supercritical carbon dioxide