Preparation and Dielectric Characterization of P(VDF–TrFE) Copolymer-Based Composites Containing Metal–Formate Frameworks

Abstract

We report the synthesis and dielectric characterization of novel polyvinylidene fluoride−trifluoroethylene P(VDF−TrFE) composite films containing [(CH 3) 2 NH 2 ][Mg(HCOO) 3 ] (DMAMg) and [NH 4 ][Zn(HCOO) 3 ] (AmZn) dense metal−organic frameworks (MOFs). The optical camera and Raman microscopies are used to map the distribution of the MOF fillers in the prepared films. The dielectric spectroscopy experiments of the DMAMg/P(VDF−TrFE) composite performed in a broad temperature range demonstrate rich dielectric behavior originating from the dipolar dynamics of the (CH 3) 2 NH 2 + molecular cations and glassy behavior of the copolymer matrix. An anomalous behavior of the complex dielectric permittivity is also observed because of the structural phase transition of DMAMg fillers. The dielectric properties of the AmZn/P(VDF−TrFE) composite film are mainly determined by the dipolar glass relaxation of the P(VDF−TrFE) polymer. The frequency-dependent dielectric spectra of both composites allow us to characterize the observed dipolar relaxation processes. The (CH 3) 2 NH 2 + cation dynamics follows the Arrhenius law, whereas the glassy behavior of P(VDF−TrFE) is described by the Vogel−Fulcher equation. For both composites, we observe a significant increase of the dielectric permittivity compared with the P(VDF−TrFE) film without MOF fillers.

Elastic Properties and Energy Loss Related to the Disorder–Order Ferroelectric Transitions in Multiferroic Metal–Organic Frameworks [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3]

“…The ferroelectric transition temperatures of [NH 4 ][Mg(HCOO) 3 ] and [(CH 3 ) 2 NH 2 ] [Mg(HCOO) 3 ] are around 255 K and 267 K, respectively, close to room temperature, leading to promising applications. Their synthesis, structure analysis, thermal properties, dielectric properties, IR studies and Raman studies have been well studied [13][14][15][33][34][35][36][37][38]57,58]. However, their elastic properties have not been reported.…”

Enhancement of permittivity in P(VDF‐CTFE)/metal–organic frameworks mixed matrix membranes

“…There have been a lot of research in other respects of such polymer/MOFs composites (namely mixed matrix membranes, MMMs), such as gas separation, sensors, even low permittivity materials. [24][25][26][27][28][29][30][31] In reported MMMs, the nanoparticles of MOFs usually can be well-dispersed in polymers matrix. In the low permittivity polymer/ MOFs composites, although the content of MOFs is relatively low, they have an obvious effect on the dielectric constant of the composites.…”