PVDF composites with spherical polymer-derived SiCN ceramic particles have significantly enhanced low-frequency dielectric constants

We report a novel functional hybrid film fabricated by using polysilazane-derived SiCN ceramics as fillers and polyvinylidene fluoride (PVDF) as the matrix. Regular spherical-shaped and amorphous SiCN ceramic powders were fabricated via a facile solvothermal method combined with a polymer-derived ceramic (PDC) process. The dielectric properties of the SiCN/PVDF composites were investigated by broadband dielectric spectroscopy from 0.1 Hz to 10⁶ Hz. The composites showed significantly enhanced low-frequency dielectric constants. When the SiCN loading content reached 40 vol%, the dielectric constant of the composites was approximately 360 at 0.1 Hz, which is 20 times the value of pure PVDF (18). The dielectric constant of the composites at 0.1 Hz fit the effective medium theory (EMT) model well. The results suggest that the SiCN/PVDF composites are promising dielectric materials and have potential use in electrical applications.