Mechanical and temperature dependence of dielectric properties for Mg1−xCuxO/PMMA nanocomposites used in energy storage applications

This study presents an innovative approach to enhancing the mechanical and dielectric properties of poly(methyl methacrylate) (PMMA) films by embedding Mg₁₋ₓCuₓO nanoparticles with varying copper content (x = 0.05 to 0.2). The nanocomposite films, fabricated via a casting technique, exhibit a remarkable improvement in dielectric performance across a wide temperature range (30–180 °C) and frequency spectrum (0.1 Hz to 1 MHz). The incorporation of Mg₁₋ₓCuₓO nanoparticles significantly boosts the dielectric constant (ε′), with values increasing at elevated temperatures, indicating superior charge storage capability-critical for next-generation electronic applications. The electric odulus analysis reveals a temperature-dependent relaxation process, with interfacial polarization effects driving the observed peaks in dielectric loss (ε″) and imaginary modulus (M″). These peaks shift to higher frequencies with rising temperatures, highlighting enhanced charge carrier mobility. Furthermore, mechanical analysis demonstrates a substantial increase in longitudinal (L), shear (G), Young’s (E), and bulk (B) moduli with higher copper concentrations, offering superior mechanical strength alongside enhanced dielectric efficiency. This research paves the way for high-performance nanocomposite materials that meet the evolving demands of flexible electronics, capacitors, and sensors, offering a unique blend of mechanical robustness and dielectric excellence.

Graphical abstract