Vibrational spectroscopy and ionic conductivity of polyethylene oxide–NaClO4–CuO nanocomposite

Structure, morphology and thermal properties of polyethylene oxide (PEO) with sodium perchlorate (NaClO4) as electrolytic salt have been investigated by incorporating cupric monoxide (CuO) nanoparticles. Monoclinic CuO affects melting and glass transition temperatures of PEO–NaClO4. Crystallinity and free ion concentration change with the variation of CuO concentration. The maximum ionic conductivity is observed for 10 wt.% CuO. Ionic conductivity follows Arrhenius type behavior as a function of temperature.

Two-dimensional atomic force image of pure polyethylene oxide presents a crystallized network of regular spherulites developing spirals and branches of well-distributed surface contours. The fitted Gaussian–Lorentzian peak to the experimental FTIR data in the ν (ClO4−) region for PEO25–NaClO4 and 10 wt.% CuO doped composite polymer electrolyte are shown in the plots (a) and (b), respectively. The ν (ClO4−) band for both the spectra has been well separated into two maxima centered at around 624 and 632 cm−1 which are related to the free anions and contact ion pairs, respectively. The peak characteristic for free anions is much larger than that representing contact–ion pairs.Figure optionsDownload as PowerPoint slideHighlights
► Structure and morphology of PEO–NaClO4 system change significantly with CuO.
► Monoclinic CuO affects melting and glass transition temperatures.
► Crystallinity and free ion concentration change with the variation of CuO content.
► The maximum ionic conductivity is observed for 10 wt.% of CuO.
► Ionic conductivity as a function of temperature follows Arrhenius type behavior.