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

Abstract

A novel family of mixed matrix membranes (MMMs) with the combination of ferroelectric fluropolymers matrix (P(VDF‐CTFE)) and ferroelectric MOFs fillers ([NH3(CH2)4NH3][M(HCOO)3]2(MCoII, MgII, and MnII), have been synthesized and characterized, including the morphology, structures, and dielectric properties. Dielectric measurements revealed that the permittivity of the composites improved notablely with the introduction of ferroelectric MOFs fillers, while the dielectric loss was comparable to that of the polymer matrix. And also, interestingly, the enhancement of permittivity evidently dependent on the quantity and dielectric behavior of MOFs fillers, which may be valuable to the dielectric regulation of the polymer/MOFs MMMs. In addition, two different preparation methods were adopted respectively, including blending and electrospinning‐hot pressing. The comparison of the two preparation methods revealed that the blending MMMs exhibit higher permittivity and higher dielectric loss than that of the electrospinning‐hot pressing MMMs. To our knowledge, this is a novel research of high‐εr dielectric MMMs fabricated by ferroelectric MOFs and ferroelectric fluropolymers, and this work may provide a new perspective on the further research of high‐κ dielectric MMMs and the industrial application of ferroelectric MOFs.

A comparison of shear‐mixing and solvent‐induced on phase behavior, thermal and dielectric properties of PVDF‐HFP/MOF composites

“…When comparing the PVDF-HFP/HImMg composite films for S and M samples, the α-phase of S at 762 cm À1 was diminished, while the 1600 cm À1 peak corresponding to asymmetric N H deformation vibration in MOF fillers (Figure S1) increased with relatively enhancing filler contents. 23 Due to slower evaporation rate, the transformation from αto β-phase can occur, resulting in an interaction between polymer and filler. This is confirmed by the wavenumber region 3060-2960 cm À1 .…”

“…Finally, the reduced thermal stability of the PVDF-HFP molecule may result from the fillers increasing the free volume fraction and reducing thermal stability, which was common in such polymer/MOF composites. 23…”

3D Printing of Polyvinylidene Fluoride Based Piezoelectric Nanocomposites: An Overview

“…[ 146 ] Furthermore, PVDF–CTFE matrix piezoelectric nanocomposites were prepared by adding BNNS and BT NPs, [ 147 ] and the reinforcement of NPs of ferroelectric metal–organic frameworks, including metal salt of Co, Mg, or Mn. [ 148 ] PVDF–TrFE–CTFE terpolymers were reinforced by TiO 2 NWs coated by SnO 2 NPs. [ 149 ] It is important to remind that only studies investigating dielectric or both dielectric and piezoelectric properties of PVDF based nanocomposites to be used in flexible electronic devices for energy harvesting and storage applications, have been staying in the scope of this review.…”

“…[67 ] Considering the conducted researches, solution casting & solvent evaporation was frequently preferred as a main or initial method to prepare PVDF based nanocomposites. [ 2,4,69,84,85,91,99,102,107,108,112,117,120,148 ] In this method, PVDF or its copolymers are firstly dissolved in a solvent (e.g., Dimethylformamide (DMF), dimethylacetamide (DMAc), acetone, 2‐butanone). Nanofillers dispersed in the same solution or different solution to obtain a homogeneous dispersion.…”

“…Electrospinning [ 96,101,148 ] spin‐coating [ 98,100,122 ] melt extrusion, [ 91,93,106 ] compression molding [ 2,85 ] injection molding, [ 106 ] powderization, [ 103 ] including three steps: pouring of solution into distilled water, solidification and removing of water, have been found as another traditional methods preferred to fabricate PVDF based nanocomposites. In some of these studies, extrusion or compression molding was performed, followed by solution casting to prevent partial sedimentation from the solution mixing, to promote the homogeneity of the composite, and to eliminate porosities with pressure.…”