A study of x-ray diffraction (XRD) and surface morphology studies of PVC complexes

In this work, the proton conducting polymer electrolytes were prepared by solution cast technique. Poly (vinyl chloride) PVC is used as the polymer host, ammonium triflate (NH4CF3SO3) as the doping salt and ethylene carbonate (EC) and butyltrimethyl ammonium bis trifluoromethyl sulfonyl imide (Bu3MeNTf2N) is used as the plasticizers. Characterization techniques of XRD and FESEM were used to study the properties of the PVC based proton conducting polymer electrolytes. XRD studies shows that amorphous PVC becomes largely amorphous in nature upon addition of NH4CF3SO3. Largely amorphous in nature is also obtained upon addition of EC and Bu3MeNTf2N to PVC-NH4CF3SO3. XRD studies of the salted samples showed that they are largely amorphous in nature. However, XRD studies could not identify for sure the most amorphous sample. Identification of the most amorphous sample is imperative as conduction in polymer electrolytes is known to occur in the amorphous region. The FESEM micrographs gave a qualitative idea of the amorphousity of the salted samples in that A4 had the most grey regions in its micrograph giving a strong indication of it being the most amorphous sample. In case of the EC plasticised system, the micrographs showed that the pore size increased with increasing concentration of EC which in turn caused the amorphous regions (grey area) to decrease. This means that B1, which has the smallest pore size and the most grey area is the most amorphous sample. In the micrographs of Bu3MeNTf2N plasticised samples, the sample C3 is observed to be more homogeneous with more white spherulites indicating presence of more trapped ionic liquid. This broadly indicates that C3 is the most amorphous due its homogeneity as compared to the sample C1.