PVC/PVP/SrTiO3 polymer blend nanocomposites as potential materials for optoelectronic applications

This paper presents, for the first time, the preparation and study of the thermal decomposition and optical properties of PVC/PVP/SrTiO3 polymer blend nanocomposites. The polymer films were characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Raman, thermogravimetric analysis (TGA), and optical spectroscopy techniques. XRD spectra indicated semicrystalline structure of the PVC/PVP polymer blend and revealed cubic crystal structure of the SrTiO3 nanoparticles. The lattice constant of SrTiO3 was found to decrease from 2.79 to 2.75 A upon increasing the concentration of the SrTiO3 nanoparticles in the blend to 0.6 wt%. The FTIR and Raman spectra revealed the strong interaction between PVC/PVP polymer blend and SrTiO3. The TGA analysis showed a slight enhancement of the polymer blend thermal stability. Moreover, the thermal kinetic parameters, such as activation energy, entropy and Gibbs free energy, of the polymer nanocomposites were lower than those of the pure PVC/PVP blend counterpart. The addition of SrTiO3 increased the optical absorption, energy gap, and linear refractive index. Furthermore, the optical susceptibility and nonlinear refractive index were significantly improved. For all polymer blends, a fluorescence peak appeared at a wavelength of 485 nm. These outcomes qualify the PVC/PVP/SrTiO3 polymer blend nanocomposites for opto-electronic applications.