Tailoring the dielectric and optical properties of PMMA through NiO nanoparticle reinforcement for opto-electronic devices

In the current research article, virgin poly(methylmethacrylate) (PMMA) including PMMA-NiO NCs films are synthesized by solvent cast technique with varied wt% of nickel oxide (NiO) (0.5, 1, 1.5 and 2 wt%) with PMMA as a host matrix. Addition of NiO into PMMA polymer, films are modified as black in colour. A comprehensive investigation of the structural and optical characteristics of the synthesized films were carried out employing X-ray diffraction (XRD), scanning electron microscopy integrated with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and UV–Visible spectroscopy. XRD result exhibits existence of NiO NPs, α-phase in the prepared films. Structural parameters of synthesized NCs determined by W-H plot. SEM analysis reveals the presence of carbon chain linkages, methyl groups, as well as spherical and fibrous morphologies in the PMMA/NiO NCs films. EDX analysis confirms the elemental composition, indicating the presence of carbon, oxygen, and nickel, and further verifies the increased weight percentage of NiO in the PMMA/NiO NCs films. FTIR analysis confirms the presence of symmetric and asymmetric stretching vibrations, along with characteristic functional groups, in both pure PMMA and PMMA/NiO NCs. Raman spectra of virgin PMMA and PMMA/NiO NCs were recorded to analyze their vibrational features. ATR spectra of prepared NCs were studied by UV-Visible spectroscopy. The optical parameters of virgin PMMA and PMMA/NiO nanocomposite films demonstrate a systematic decline with increasing NiO content by weight. However, an enhancement in refractive index (n), real (εᵣ) and imaginary (εᵢ) parts of the dielectric constant, optical conductivity (σ), high-frequency dielectric constant (ε ∞ ), and carrier density-to-effective mass ratio is observed. These variations are attributed to intensified dipole polarization interactions within the nanocomposite matrix. Optical dispersion parameters were evaluated using the single oscillator model (SOM). Obtained values exhibited fluctuations by NiO NPs (wt%) content, which is attributed to electronic transitions between the PMMA matrix and the NiO NPs.