The effects of dopant on morphology formation in polyaniline graphite nanoplatelet composite

In this study, a nanocomposite (SELA-PANi/GNP) consisting of selenious acid (SELA) doped polyaniline (PANi) and graphite nanoplatelet (GNP) was prepared, and its structure and properties – in particular, morphology formation, as well as interaction between the two phases – were investigated using scanning electron microscopy (SEM), UV–vis spectroscopy, FTIR spectroscopy, X-ray diffraction, and electrical conductivity measurement. A PANi/GNP nanocomposite prepared in aqueous HCl solution (HCl-PANi/GNP) was also prepared for comparison with SELA-PANi/GNP. The results reveal that the dopant plays an important role in morphology formation in PANi/GNP nanocomposites. When HCl was used as the dopant, PANi coated GNPs were formed and no phase separation between PANi and GNP was seen. In contrast, when SELA was used as the dopant, the morphology of PANi remained unchanged in the composite, owing to the formation of rod or sphere micelle PANi structure during in situ polymerization; no interaction was observed between the two phases. The crystalline structure of PANi was not affected by the incorporation of GNP. The electrical conductivity of PANi/GNP increased with increasing GNP content, because of the electrical bridge effect of GNP in the PANi matrix.