Spectroscopic, electrical, and relaxor-like properties of cellulose acetate-erbium (III) chloride composite films

Cellulose acetate thin films doped with erbium (III) chloride (ErCl3) of different concentrations were prepared by the solution method. The prepared composite films were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis. IR spectral analysis, UV-visible absorption, a.c. conductivity, and dielectric properties were investigated. The studied ErCl3-doped samples showed different properties from those of their pure components. SEM micrographs showed that for small dopant concentrations, samples tend to form conducting nanostructures with negligible particle agglomeration. DSC showed a monotonic development of the glass transition temperature by increasing the concentration of dopant material. Variation in the height, shape, and position of the bands in infrared transmission spectra, as well as the glass transition temperatures, indicated a complex interaction with the polymer molecular chains. Thermal stability and thermodynamic parameters were found to be concentration dependent. The electronic transitions' band gabs and energy tails were calculated from the optical data. The dielectric studies showed that the correlated barrier hopping model was the dominant mechanism of a.c. conductivity. We found that samples with 10% and 20% ErCl3 exhibited high dielectric constants and have pronounced electrostriction and relaxor-like properties. Such samples can be used in many applications like electromechanical and thermomechanical transducers. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45220.