Synthesis of exfoliated polyaniline–clay nanocomposite in supercritical CO2

This paper presents the works done to synthesize fully exfoliated polyaniline–clay nanocomposites (PCNs) with high purity via in situ polymerization of aniline in Cloisite 30B nano-clay suspension in supercritical CO2 (ScCO2) medium. The Cloisite 30B was first delaminated with ScCO2 treatment in the presence of aniline monomers. Ammonium peroxydisulfate (APS) solution was added rapidly into the mixture of delaminated Cloisite 30B and aniline monomers to produce PCNs. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy and XRD analysis have been used to characterize the morphology and structure of the as-synthesized product. SEM results reveal that nano-clays are fully exfoliated in the final nanocomposite which is synthesized in ScCO2. FTIR and UV–vis analysis showed that the resulted polyaniline (PANI) had been in highly conductive emeraldine salt state and ScCO2 does not have any effect on chemical structures of the PANI.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Two-step process was used to prepare exfoliated polyaniline–clay nanocomposite. ► Cloisite 30B was delaminated in the presence of monomers using supercritical CO2. ► Polymerization was carried out in supercritical CO2 to achieve nanocomposite. ► Autoclave was de-pressurized rapidly to obtain fully exfoliated nanocomposite.