Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transference number measurement (TNM) techniques were applied to investigate the complexation, structural, and ionic transport properties of and the dominant charge-carrier species in a solid biopolymer electrolyte (SBE) system based on carboxymethyl cellulose (CMC) doped with ammonium fluoride (NH4F), which was prepared via a solution casting technique. The SBEs were partially opaque in appearance, with no phase separation. The presence of interactions between the host polymer (CMC) and the ionic dopant (NH4F) was proven by FT-IR analysis at the C-O band. XRD spectra analyzed using Origin 8 software disclose that the degree of crystallinity (χc%) of the SBEs decreased with the addition of NH4F, indicating an increase in the amorphous nature of the SBEs. Analysis of the ionic transport properties reveals that the ionic conductivity of the SBEs is dependent on the ionic mobility (μ) and diffusion of ions (D). TNM analysis confirms that the SBEs are proton conductors.
Addition of doping materials can possibly enhance the ionic conduction of solid polymer electrolyte (SPE). In this work, a new SPE using 2-hydroxyethyl cellulose (2-HEC) incorporated with different ammonium nitrate (NH4NO3) composition was prepared via solution casting method. Studies of structural properties were conducted to correlate the ionic conductivity of 2-HECNH4NO3SPE using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Encouraging result was obtained as the ionic conductivity increased about two orders of magnitude upon addition of 12wt% of NH4NO3. XRD analysis shows the most amorphous SPE was obtained at 12-NH4NO3. From FTIR spectra, the interactions between 2-HEC and NH4NO3were observed by the shifts of COH peak from 1355cm-1to 1330cm-1and the presence of new NH peak in the OH region. The spectrum has been validated theoretically using Gaussian software. The results obtained from this study corroborate that the complexes of 2-HEC and NH4NO3responsible to promote the ionic conductivity to the higher value.
The plasticized solid bio-polymer electrolytes (SBEs) system has been formed by introducing glycerol (Gly) as the plasticizer into the carboxymethyl cellulose (CMC) doped with oleic acid (OA) via solution casting techniques. The ionic conductivity of the plasticized SBEs has been studied using Electrical Impedance Spectroscopy. The highest conductivity achieved is 1.64 × 10(-4) S cm(-1) for system containing 40 wt. % of glycerol. FTIR deconvolution technique had shown that the conductivity of CMC-OA-Gly SBEs is primarily influenced by the number density of mobile ions. Transference number measurement has shown that the cation diffusion coefficient and ionic mobility is higher than anion which proved the plasticized polymer system is a proton conductor.