resumo
Poly vinylidene fluoride (PVDF)-based nanocomposite films comprising varying amounts of surface-modified BaTiO3 nanotubes (BT NTs) and nanofibers (BT NFs) were prepared using tape casting process and subsequent re-melting at 200 degrees C. The obtained nanocomposite films were studied in terms of microstructure, dielectric properties and energy storage performance. The microstructural investigations showed the relatively uniform dispersion of the BT NTs and BT NFs nanofillers inside the PVDF matrix. At the frequency of 100 Hz, the relative dielectric constant (epsilon r) of nanocomposites containing 14.3 vol% BT NTs and BT NFs, exhibited significant enhancements of approximately 356 % and 242 %, respectively. The significant reduction in dielectric loss at 1000 Hz, along with the nearly identical values observed, suggested a reduced effectiveness of interfacial polarization at this frequency. The nanocomposites containing BT NTs showed lower dielectric breakdown strength and slightly higher dielectric loss factor in comparison to the nanocomposites filled with BT NFs. A maximum recoverable energy storage density of 4.6 J/cm3 was achieved for the nanocomposite containing 2.7 vol% BT NTs, which is slightly higher than that observed for nanocomposite with 2.7 vol% BT NFs (4.2 J/cm3). These values correspond to improvements of approximately 53.7 % and 41.2 %, respectively, compared to the pristine PVDF film (2.9 J/cm3).
palavras-chave
POLYMER COMPOSITES; FERROELECTRIC POLYMER; BREAKDOWN STRENGTH; HIGH-TEMPERATURE; DENSITY; PERFORMANCE; CAPACITORS; CONSTANT; FILMS
categoria
Materials Science
autores
Hedayati, M; Taheri-Nassaj, E; Yourdkhani, A; Rasekh, S; Sebastian, T; Clemens, FJ
nossos autores
agradecimentos
The authors gratefully acknowledge Empa, Swiss Federal Laboratories for Materials Science and Technology, for their support in providing materials and equipment. This project was also partially financial supported by the Ministry of Science, Research and Technology of Iran. Sh. Rasekh acknowledges the support of the Research Employment Contract FCT- CEECIND/02608/2017.

