Development of PVDF/PMMA-Cu nanocomposites with enhanced dielectric properties and energy storage density for capacitor applications

This study aims to develop novel PVDF/PMMA-based polymer nanocomposites (PNCs) filled with copper nanoparticles (Cu NPs) for capacitive energy storage applications. The unique conductive properties of Cu NPs were utilized to enhance the dielectric and energy storage properties of the polymer blend significantly. Cu NPs were incorporated at low concentrations (1.5 and 3 wt.%), providing a cost-effective approach to improving material performance. Structural analyses using XRD and FTIR revealed that Cu NPs disrupt the crystalline structure of the polymer blend, increasing the amorphous phase and facilitating charge carrier mobility. UV/visible spectroscopy demonstrated a reduction in the optical bandgap energy, indicating strong electronic interactions between Cu NPs and the polymer matrix. Impedance spectroscopy and dielectric measurements confirmed that Cu NPs enhance interfacial polarization, resulting in higher dielectric constants and improved conductivity at low frequencies while maintaining low dielectric loss. Notably, the 3 wt.% Cu NP nanocomposite achieved an energy storage density of ~3.8 × 10⁻³ J/m³ at low frequencies, more than double that of the pure PVDF/PMMA blend. These findings indicate that PVDF/PMMA-Cu nanocomposites could be promising materials for capacitive energy storage applications.

Highlights

• PVDF/PMMA/Cu nanocomposites were prepared using the solution-casting method.
• CuNPs in PVDF/PMMA blends enhance optical, structural, and electrical properties.
• Improved dielectric properties and conductivity in PNCs were demonstrated.
• Fabricated capacitors exhibited improved performance and higher energy storage.