Synthesis of polyaniline in electrospun microfibers via in-situ polymerization and the formation of self-assemble polyaniline particles

This study reports on the synthesis of the polyaniline (PANi) in electrospun poly(vinylchloride-acrylonitrile) (PVC-AN) via in-situ oxidative polymerization of aniline using ammonium peroxydisulfate (APS) as the oxidant. Self-assemble polyaniline nano-particles were obtained from dissolving the conductive microfibers in dimethylformamide (DMF). The formation of PANi in microfibers can be explained by electrons transformation process, in which the electrons are abstracted from the aniline molecules in the microfibers and transferred through a conducting PANI membrane to APS in the external solution. Thus the aniline was oxidized without physically contact with oxidant molecules. The average diameter of conductive fibers was about 1.0 mu m; and the particles had average diameters around 350 nm and inclined to aggregate to become much larger particles with the diameter up to 2.0 mu m based on the scanning electron microscope (SEM) images. The differences in the details of molecular structure between PVC-AN fibers, PANi and PVC-AN-PANi fibers were discussed on the basis of FTIR spectra. Results from Differential scanning calorimetry analysis (DSC) and X-ray diffraction (XRD) indicated the PVC-AN-PANi microfibers form an interpenetrating polymer network (IPN) structured complex with certain molecular interactions.