Influence of polymerization routes on the crystalline behavior of polyaniline salt

The effects of polymerization routes on the crystalline nature of polyaniline (PANI) salts were investigated. PANI salts were prepared by two effective pathways, i.e. emulsion polymerization (Bilal, et al., 2014) and inverse emulsion polymerization (Bilal, et al., 2012). Scanning electron micrographs (SEM) present the irregular granular morphology of these PANI salts having different particle sizes. The effect was further assessed by X-ray diffraction (XRD) in detail. The results showed that interchain separation and crystallite size of the PANI salts were affected by the synthesis methods. The small crystallite size and interchain separation of PANI salt prepared by emulsion polymerization suggested its good electrical properties compared to the PANI salt prepared by inverse emulsion polymerization. The results were further supported by energy band gap values calculated by using UV-Vis spectra. All these results demonstrate that emulsion polymerization enhanced the crystalline behavior by inducing more ordered structure of PANI salt, which can be readily used in optoelectronic devises. (author)