Spray deposition of polymer nanocomposite films for dielectric applications

A scalable processing route for fabrication of polymer-based dielectric nanocomposite films has been developed by spray deposition and in situ polymerization of monomer-nanoparticle dispersions. Polydiacrylate-BaTiO3 films with filler loadings of 10 vol% to 30 vol% and controlled thickness of 5-30 μm were achieved by optimizing spray conditions of spray liquid flow rate, atomizing gas pressure and substrate traverse speed and temperature. Microstructural investigations showed well-dispersed BaTiO3 nanoparticles embedded in the polydiacrylate matrix. Dielectric constants of ∼ 39 at 10 kHz, high breakdown strengths of >100 kV/mm and low leakage currents of 10−9 to 10−8 A/cm2 above 1000 V, and thermal stability up to 150 °C were attained for PTPGDA-30 vol%BaTiO3 films. The low-cost, atmospheric spray deposition technique developed in this work has potential for larger-scale manufacture of dielectric nanocomposite films for power capacitor and other applications.