Large Dielectric Constant and High Thermal Conductivity in Poly(vinylidene fluoride)/Barium Titanate/Silicon Carbide Three-Phase Nanocomposites

Abstract

Dielectric polymer composites with high dielectric constants and high thermal conductivity have many potential applications in modern electronic and electrical industry. In this study, three-phase composites comprising poly(vinylidene fluoride) (PVDF), barium titanate (BT) nanoparticles, and β-silicon carbide (β-SiC) whiskers were prepared. The superiority of this method is that, when compared with the two-phase PVDF/BT composites, three-phase composites not only show significantly increased dielectric constants but also have higher thermal conductivity. Our results show that the addition of 17.5 vol % β-SiC whiskers increases the dielectric constants of PVDF/BT nanocomposites from 39 to 325 at 1000 Hz, while the addition of 20.0 vol % β-SiC whiskers increases the thermal conductivity of PVDF/BT nanocomposites from 1.05 to 1.68 W m(-1) K(-1) at 25 °C. PVDF/β-SiC composites were also prepared for comparative research. It was found that PVDF/BT/β-SiC composites show much higher dielectric constants in comparison with the PVDF/β-SiC composites within 17.5 vol % β-SiC. The PVDF/β-SiC composites show dielectric constants comparable to those of the three-phase composites only when the β-SiC volume fraction is 20.0%, whereas the dielectric loss of the PVDF/β-SiC composites was much higher than that of the three-phase composites. The frequency dependence of the dielectric property for the composites was investigated by using broad-band (10(-2)-10(6) Hz) dielectric spectroscopy.

Polyvinylidene fluoride/vanadium pentoxide composites with high dielectric constant and low dielectric loss

“…Compared with the reported ceramic/PVDF composites and conductive metal Zn/PVDF [5,7,9,20,21], the dielectric constant of PVDF/V 2 O 5 composites is significantly higher at low filler content. Furthermore, it can be obviously found that our V 2 O 5 /PVDF composites possess higher dielectric constant than other semiconductor/polymers nanocomposites, such as ZnO/PVDF, TiO 2 /polystyrene, and ZnO/ polyethylene reported at a low filler content [10,22,23].…”

“…Thus, it is a key issue to enhance dielectric permittivity of polymers while retaining other excellent performances. One versatile route is to disperse a high dielectric constant ceramic powder [5,6] into the polymer matrix [7][8][9], which can combine excellent dielectric behavior of fillers with superior processing property and chemical stability from the polymers. However, the excellent dielectric properties of such composites need high particle concentration (over 60 vol%), which can lead to the degradation of mechanical properties and processability of the polymers.…”

Dielectric and current–voltage characteristics of flexible Ag/BaTiO3 nanocomposite films processed at near room temperature

“…Our results are close enough to the ideal region by demonstrating the dielectric constant of $303 with a loss of $0.08. The composite cases with higher 3 r than our value are based on thermally cured bulk samples heat-treated at 160 to 200 C. 15,17,34 The yellow highlighted region in the le bottom region of Fig. 8 corresponds to the BaTiO 3 -based composite examples not containing percolative metal particles, 10,35-37 which can be characterized with low dielectric constant with acceptable dielectric loss.…”

Preparation and Characterization of Pure Organic Dielectric Composites for Capacitors

“…A series of related studies has been proposed to solve this problem [14][15][16][17]. A general method is to use high k materials as fillers to significantly improve the dielectric properties of polymers [18][19][20][21][22][23]. It is well known that polyvinylidene fluoride (PVDF) has a relatively high dielectric constant (10)(11)(12)(13)(14) [24,25] which can be used as a high dielectric filler to improve the dielectric constant of PI.…”