In this work, a synthesis technique for highly homogeneous PVDF-CaFe₂O₄ polymer films direct from solution was developed. The structural characterizations were conducted using XRD, FTIR, and ESEM experimental techniques. The XRD characteristic peaks of CaFe₂O₄ nanoparticles revealed a polycrystalline structure. The average crystallite size for CaFe₂O₄ was calculated to be 17.0 nm. ESEM micrographs of PVDF nanocomposites containing 0.0, 0.25, 0.75, and 1.0 wt% of CaFe₂O₄ showed smooth surface topography. The direct E_dir and indirect E_ind band gap energies for the PVDF-CaFe₂O₄ nanocomposites were decreased with the additions of 0.0–1.0 wt% CaFe₂O₄. In addition, the refractive index (n₀) increased from 3.38 to 10.36, and energy gaps (E_g) decreased from 5.50 to 4.95 eV. The nonlinear refractive index (n₂) for the PVDF-CaFe₂O₄ nanocomposites was improved with the addition of CaFe₂O₄ nanoparticles, exceeding those reported in the literature for PVC, PVA, and PMMA nanocomposites. Therefore, the PVDF-CaFe₂O₄ nanocomposites are expected to take the lead in optoelectronic applications because of their unusual optical properties.

The present work considers the integration of g-C₃N₄ nanosheets into PVC/PVP polymer nanocomposites at ratios of 0.0, 0.3, 0.6, and 1.0 wt%. The XRD data scans showed semicrystalline structures for all PVC/PVP/g-C₃N₄ polymer blend films. The FTIR and Raman measurements revealed intermolecular hydrogen bonding between the g-C₃N₄ surface and the OH⁻ groups of the PVC/PVP network. ESEM morphology analysis for PVC/PVP/g-C₃N₄ nanocomposite films displayed homogeneous surface textures. The data of TGA showed improved thermal stability as the decomposition temperature increased from 262 to 276 °C with the content of g-C₃N₄ (0.0–1.0 wt%). The optical absorbance data for PVC/PVP films improved after the addition of g-C₃N₄. The optical energy gaps showed compositional dependence on the g-C₃N₄ content, which changed from 5.23 to 5.34 eV at indirect allowed transitions. The refractive index for these blend films enhanced (1.83–3.96) with the inclusion of g-C₃N₄. Moreover, the optical susceptibility for these nanocomposite films increased as the content of g-C₃N₄ changed from 0.0 to 1.0 wt%. Finally, the values of the nonlinear refractive index showed improvement with the increased percentage of g-C₃N₄. When g-C₃N₄ was added up to 1.0 wt%, the DC conductivity improved from 4.21 × 10⁻⁸ to 1.78 × 10⁻⁶ S/cm. The outcomes of this study prove the suitable application of PVC/PVP/g-C₃N₄ in optoelectronic fiber sensors.

Successful preparation of PVA/SrTiO₃/CNT polymer nanocomposite films was accomplished via the solution casting method. The structural, optical, and thermal properties of the films were tested by XRD, SEM, FTIR, TGA, and UV-visible spectroscopy. Inclusion of the SrTiO₃/CNT nanofillers with a maximum of 1 wt% drastically improved the optical and thermal properties of PVA films. SrTiO₃ has a cubic crystal structure, and its average crystal size was found to be 28.75 nm. SEM images showed uniform distribution in the sample with 0.3 wt% of SrTiO₃/CNTs in the PVA film, while some agglomerations appeared in the samples of higher SrTiO₃/CNT content, i.e., at 0.7 and 1.0 wt%, in the PVA polymer films. The inclusion of SrTiO₃/CNTs improved the thermal stability of PVA polymer films. The direct and indirect optical band gaps of the PVA films decreased when increasing the mass of the SrTiO₃/CNTs, while the single-oscillator energy (E₀) and dispersion energy (E_d) increased. The films’ refractive indices were gradually increased upon increasing the nanofillers’ weight. In addition, improvements in the optical susceptibility and nonlinear refractive indices’ values were also obtained. These films are qualified for optoelectronic applications due to their distinct optical and thermal properties.

The optical properties of polyvinylidene fluoride (PVDF) polymer nanocomposite films incorporating SrTiO₃/carbon nanotubes (CNTs) as nanofillers are investigated. PVDF/SrTiO₃/CNTs films were prepared by the solution casting technique. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses confirmed the incorporation of SrTiO₃/CNTs into the PVDF matrix. The addition of nanofillers influenced the crystalline structure, morphology, and optical properties of the films. SEM images showed spherulite morphology, which is a spherical aggregate of crystalline polymer chains. The addition of a SrTiO₃/CNTs nanofiller modified the polymer’s electronic structure, causing a variation in the energy gap. The addition of SrTiO₃/CNTs at 0.1 wt% increased the band gap, refractive index, and nonlinear optical properties of the PVDF films. These improvements indicate the potential of these nanocomposite films in optoelectronic applications such as solar cells, image sensors, and organic light-emitting diodes.

Polymer blend hybrid nanocomposites are of great importance for future optoelectronic applications. This paper presents the preparation of new polymer blend hybrid nanocomposites based on PVC/PVP modified with Er₂O₃ nanoparticles. A low-cost solution casting method has been used to prepare the polymer nanocomposites at 0.0, 0.1, 0.3 and 0.6 wt% of Er₂O₃. X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectroscopy, and environmental scanning electron microscopy (ESEM) measurements have all been used to examine the impact of a varying wt% of Er₂O₃ on the structural and optical characteristics of PVP/PVC polymer blends. The PVC/PVP polymer blend and Er₂O₃ nanoparticles showed a strong interaction, which was validated by XRD, FTIR, and Raman spectrum investigations. The SEM micrographs showed a remarkable complexation among the components of the polymer nanocomposites. The activation energies for thermal decomposition of PVC/PVP doped with different Er₂O₃ concentrations were less than that of the pure polymer film. The linear and nonlinear refractive indexes, dispersion energy, optical susceptibility and the energy gap values were found to be Er₂O₃ concentration-dependent. With an increase in Er₂O₃ concentration to 0.1 and 0.3 wt%, the dispersion energy and nonlinear refractive index improved, and thereafter decreased when the concentration was further increased to 0.6For the film doped with 0.1 wt% Er₂O₃, the optical band gap (E_opt) of the composite film enhanced by about 13%. The optical absorption measurements revealed clear improvements with the addition of erbium oxide. Higher refractive index values of PVC/PVP/Er₂O₃ films qualify the polymer blend as a cladding for electro-optic modulators. Our results indicated that the PVC/PVP/Er₂O₃ polymer films could be suitable for optoelectronic space applications.

Polyvinyl alcohol (PVA) and Neodymium (III) oxide (Nd₂O₃) were combined to synthesized flexible innovative PVA/Nd₂O₃ polymer composite samples utilizing a solution casting approach for use in dielectric devices. The XRD, FTIR, and SEM methods are all investigated to characterize the composite films. In a frequency of 50 Hz to 5 MHz, the effects of additive Nd₂O₃ on the dielectric behavior of PVA were recorded. The PVA/Nd₂O₃ composite films were successfully fabricated, as shown by XRD and infrared spectroscopy. The scanning microscopy pictures showed that the Nd₂O₃ was loaded and distributed uniformly throughout the PVA. After the incorporation of Nd₂O₃, the composite PVA/Nd₂O₃ has a conductivity of 6.82 $\times$ 10⁻⁹ S·cm⁻¹, while the PVA has a conductivity of 0.82 $\times$ 10⁻⁹ S·cm⁻¹. Another improvement is the decrease in the relaxation time from 14.2 $\times$ 10⁻⁵ s for PVA to 6.35 $\times$ 10⁻⁵ s for PVA/Nd₂O₃, and an increase in the dielectric constant of 0.237 for PVA to 0.484 at a frequency of 100 Hz. The results showed that the composite samples have considerable changes as flexible films in different applications, including batteries and electronic circuits.