Tunable β-phase crystals, degree of crystallinity, and dielectric properties of three-phase PVDF/PEO/SiO_2 hybrid polymer nanocomposites

摘要

Polymer nanocomposites (PNCs) are key materials in the advances of flexible-type microelectronic devices based on polymer engineering and technology. In this study, three-phase hybrid PNC films of poly(vinylidene fluoride)/poly(ethylene oxide) (PVDF/PEO) blend dispersed with amorphous silica (SiO2) nanoparticles were prepared and characterized by different spectroscopic techniques. The results reveal that the increase of SiO2 contents decreases the degree of crystallinity and relative fraction of PVDF beta-phase crystals, and considerably modifies the spherulitic morphology of PVDF/PEO blend matrix. The dielectric spectroscopy of frequency range 20 Hz-1 MHz confirms a dominant contribution of interfacial polarization at low frequencies and a significant hindrance to the PEO chain segmental dynamics. Furthermore, the dielectric permittivity of these films increases linearly up to 5 wt% loading of nanofiller. The tunable structural and dielectric properties of the PVDF/PEO/SiO2 films with SiO2 concentration confirm them technologically appealing polymeric nanodielectrics for energy storage and organoelectronic device applications.