Ion Exchange Dependent Electroactive Phase Content and Electrical Properties of Poly(vinylidene fluoride)/Na(M)Y Composites

Abstract

Different metal ion exchanged NaY zeolite, Na(M)Y, were used to prepare poly(vinylidene fluoride) based composites by solvent casting and melting crystallization. The effect of different metal ion exchanged zeolites on polymer crystallization and electrical properties was reported. Cation−framework interactions and hydration energy of the cations determined that K + is the most efficient exchanged ion in NaY zeolite, followed by Cs + and Li + . The electroactive phase crystallization strongly depends on the ions present in the zeolite, leading to variations of the surface energy characteristics of the Na(M)Y zeolites and the polymer chain ability of penetration in the zeolite. Thus, Na(Li)Y and NaY induce the complete electroactive γ-phase crystallization of the crystalline phase of PVDF, while Na(K)Y only induces it partly and Na(Cs)Y is not able to promote the crystallization of the electroactive phase. Furthermore, different ion size/weight and different interaction with the zeolite framework result in significant variations in the electrical response of the composite. In this way, iinterfacial polarization effects in the zeolite cavities and zeolite−polymer interface lead to strong increases of the dielectric constant on the composites with lightest ions weakly bound to the zeolite framework. Polymer composites with Na(Li)Y show the highest dielectric response, followed by NaY and Na(K)Y. Zeolite Na(Cs)Y contributes to a decrease of the dielectric constant of the composite. The results show the relevance of the materials for sensor development.

On The Multiscale Structure and Morphology of PVDF‐HFP@MOF Membranes in The Scope of Water Remediation Applications

“…This trend has also been reported for PVDF composites, including other inorganic and organic fillers. [45,50,51] In line with the thermogravimetric analyses, the DSC measurements of the PVDF-HFP and PVDF-HFP@MOF samples (Figure 2d; Figure S2d, Supporting Information) exhibit characteristic endothermic peaks that correspond to the melting temperature of the polymer (≈140 °C), but also to an endothermic process (60-90 °C) related to the dehydration of the MOFs. On the other hand, during cooling, the crystallization of the polymer is detected by the peak at ≈100 °C.…”

Metal–Organic Framework Based PVDF Separators for High Rate Cycling Lithium-Ion Batteries

“…Taking into consideration that the X-ray beam penetration within the sample is limited, XRD data suggest the existence of a MOF-808 nanoparticles gradient within the membrane, being a lower MOF content at the membrane surface (Figure S4). A side effect of the MOF-808 incorporation within PVDF membranes is a slight increase of the β-phase content within the PVDF porous support, as it has been reported for PVDF composites on the basis of metal oxide or zeolite nanoparticles for the crystallization of the γ-phase …”

Multiscale-structuring of polyvinylidene fluoride for energy harvesting: the impact of molecular-, micro- and macro-structure

“…For PVDF composites lled with Na(M)Y zeolites, the negatively charged zeolite framework induces the formation of the polar g-phase in PVDF when prepared by solution-cast and melt compression. 114 The use of Na(Y) in the composite induced 100% of g-phase in PVDF due to the negatively charged iondipole interactions between the zeolite framework and the PVDF. The exchangeable (M) ion size in the zeolite also affects the PVDF phase structure.…”