Exploring the structural, optical and electrical characteristics of PVA/PANi blends

Abstract

Polyvinyl alcohol (PVA)/x wt.% polyaniline (PANi) (x = 0, 0.25, 0.5, 0.75, 1) polymer blends were formed using the casting method. X-ray diffraction technique was employed to examine the homogeneity and crystallinity of obtained PANi/PVA matrix. The effect of PANi ratio on the absorbance, absorption edge, transmittance, reflectance, refractive index, extinction coefficients and fluorescence (FL) behaviors of the blends was explored. The optical band gap of PVA decreased as it loaded with PANi. The FL intensity of pure PVA is very slight and dramatically enhanced by adding PANi, attained maximum for x = 1.0 wt %. The obtained direct and indirect bandgaps of PVA are 5.31 and 5.04 eV, respectively, and exhibited a reducing trend as the PANi content (x) increased, reached their lowest values (3.03, 2.35) eV for x = 1.0 wt %. The influence of PANi content on the dielectric constant and AC electrical conductivity of the obtained blends was also examined at room temperature. The blend with 0.25 wt% of PANi disclosed the optimal DC conductivity. The activation energy value of PVA (0.44 eV) varied non monotonically with PANi content (x), achieved its lowest value (0.21 eV) for x = 0.75 wt% and largest value (0.57 eV) for x = 1.0 wt %.