Effect of nano fillers on electrical, mechanical, fluorescent and third order non linear optical properties of PVA

Abstract

This paper explores the preparation of TiO2, MoO3 nanoparticles and PVA/(x)TiO2(15−x) MoO3 nanocomposites for filling concentration x = 0, 1, 5, 7.5, 10, 14 and 15 wt% via solution casting method. The XRD spectra of prepared samples confirm the formation of nanocomposites based on the observation of the peaks representing PVA and TiO2, MoO3 nanoparticles. The aforementioned reconnoitres the crystalline parameters specifying a high percentage crystallinity for x = 10 wt% filling concentration. The structural confirmations of nanocomposites are done using FTIR spectroscopy. The UV-Vis studies also reflects the same trend of decreasing energy gap for x = 10 wt% filling concentration. This surveillance is due to the interaction of added dopants with the OH group of host PVA. IV studies spectacles a high conductivity and low resistance for x = 10 wt% optimum filling concentration. The UTM explores the high tensile strength and Young’s modulus for x = 10 wt% filling concentration. The surface morphological studies determined by means of AFM shows average roughness of 125.3 nm. Photoluminescence studies gives an emission band at 390 nm corresponds to the surface trap induced effects and intense emission band at 680 nm resemble the electron hole recombination of TiO2 and MoO3 nanoparticles. AC conductivity shows that the conductivity increases for different doping concentrations with the rise in frequency. The frequency dependent dielectric constants with various doping concentrations of the prepared nanocomposites have been recorded. Using Z-scan technique the sign and magnitude of the third-order NLO properties of prepared nanocomposites were studied. From closed and open aperture Z-scan statistics it is perceived that the material exhibit strong two-photon absorption (2PA) with the nonlinear absorption (NLA) coefficients (β), nonlinear refractive index (NRI) and third order Non-linear optical susceptibility (χ3).