Development of high-dielectric constant polymethyl methacrylate composites doped with tin oxide nanoparticles for...

In this study, new polymethyl methacrylate (PMMA) composites were developed by doping with tin oxide (SnO₂) nanoparticles at varying concentrations (2%, 5%, 10%, and 20% by weight) via solution casting. The dielectric properties and alternating current (AC) conductivity of SnO₂/PMMA were examined. The impact of SnO₂ ratio, frequency and temperatures on the electrical properties were investigated. Unlike previous studies with limited conditions, our work systematically explores a broad frequency-temperature range, revealing deeper insights into interfacial polarization and charge transport. Results showed that the doping with SnO₂ nanoparticles significantly enhanced the dielectric constant (ε'), particularly at lower frequencies, due to increased interfacial polarization (Maxwell-Wagner-Sillars effect). The dielectric loss (ε″) also increased with SnO₂ content and temperature, reflecting enhanced interfacial polarization and restricted polymer chain mobility. The AC conductivity followed a power-law dependence on frequency, indicating charge hopping mechanisms, with higher conductivities observed in SnO₂-doped PMMA. The real and imaginary parts of the electric modulus (M' and M″) increased with nanoparticle content, suggesting improved dielectric relaxation. These results demonstrate that SnO₂ nanoparticles effectively enhance the dielectric and conductive properties of PMMA, making these composites suitable for advanced electronic applications.