Effect of electron irradiation on electroactive phase and dielectric properties of PVDF films

Ye, Huijian; Shao, Wen‐Zhu; Li, Yang; Sun, Song-Bai; Zhen, Liang

doi:10.1039/c3ra47550f

Cited by 19 publications

(13 citation statements)

References 38 publications

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“…Whereas air has a low dielectric constant , by reduction of void volume, the air content inside samples decreases resulting in an increase in the dielectric constant [ 18 ]. On the contrary Hui-Jian Ye et al observed that the dielectric constant of PVDF film decreased by increasing the EB dose since the samples they used were films rather than membranes [ 12 ].…”

Section: Resultsmentioning

confidence: 99%

“…Changes in crystallinity, melting point, gel fraction and crosslinking of PVDF film by EB irradiation have been reported [ 8 , 9 , 10 , 11 ]. Also, Hui-Jian Ye et al [ 12 ] investigated the effect of electron irradiation on the electroactive phase and dielectric properties of PVDF films. The results show a reducing trend for the relative content of β-phase, crystallinity, dielectric constant and the maximum exothermal temperature of PVDF films with increasing doses.…”

Section: Introductionmentioning

confidence: 99%

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Characteristics of PVDF Membranes Irradiated by Electron Beam

et al. 2015

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Polyvinylidene fluoride (PVDF) membranes were exposed vertically to a high energy electron beam (EB) in air, at room temperature. The chemical changes were examined by Fourier Transform Infrared Spectroscopy (FTIR). The surface morphologies were studied by Scanning Electron Microscopy (SEM) and showed some changes in the pore size. Thermogravimetric (TGA) analysis represented an increase in the thermal stability of PVDF due to irradiation. Electron paramagnetic resonance (EPR) showed the presence of free radicals in the irradiated PVDF. The effect of EB irradiation on the electrical properties of the membranes was analyzed in order to determine the dielectric constant, and an increase in the dielectric constant was found on increasing the dose. The surface hydrophilicity of the modified membrane was characterized by water contact angle measurement. The contact angle decreased compared to the original angle, indicating an improvement of surface hydrophilicity. Filtration results also showed that the pure water flux (PWF) of the modified membrane was lower than that of the unirradiated membrane.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characteristics of PVDF Membranes Irradiated by Electron Beam

et al. 2015

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“…It is known that the electroactive β phase of PVDF can be obtained by stretching the polymer chains in α phase; the mechanical tension applied to a film sample leads to an alignment of the polymer chains with consequent conversion into β phase . In particular, it was studied that the amount of β phase obtained is influenced by stretching temperature, rate, and ratio . However, despite the effectiveness of this method in yielding the β phase of PVDF, hard stretching conditions can promote the formation of defects within the polymer, leading to a deterioration of its electric performances.…”

Section: Resultsmentioning

confidence: 99%

“…The polymorphism of the PVDF matrix was investigated through this technique: as suggested by Cai et al . and other authors, the relative fraction of the electroactive phase ( F EA ), in terms of crystalline components, can be determined by:

F_{EA} = \frac{I_{EA}}{1.26 I_{α} + I_{EA}} * 100

where I EA is the absorbance of the band at about 840 cm −1 (assigned to β and/or γ phase), I α is the absorbance at 763 cm −1 (characteristic of the α phase), and 1.26 is the ratio between the absorption coefficients at the respective wavenumbers.…”

Section: Methodsmentioning

confidence: 99%

“…Besides the application of high electric fields, crystallization from solvents at temperatures below 70 °C and blending with others polymers, other strategies are employed to promote the formation of the β phase, involving the use of mechanical stresses. In particular, as reported in literature, stretching or rolling are widely used to induce the formation of β phase from the α phase or to increase the electroactive form amount. Most of these studies are focused on the neat PVDF polymer.…”

Section: Introductionmentioning

confidence: 99%

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PVDF‐based composites containing PZT particles: How processing affects the final properties

Brunengo

Castellano

Conzatti

et al. 2020

J of Applied Polymer Sci

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Poly(vinylidene fluoride) (PVDF)‐based composites containing up to 30 vol % of lead zirconate titanate (PZT) particles were prepared by: (a) different techniques, melt blending and solvent casting; and (b) different molding procedures, a single‐step and a two‐step hot‐pressing method. The obtained samples were characterized in order to study how the processing affects their final properties. Results indicate that the different molding processes have a strong effect on polymorphism and molecular relaxations of PVDF as well as on dielectric response of the composite materials, that results enhanced by the two‐step molding. The preparation technique influences the filler dispersion and, consequently, the elastic modulus of the composites, but without remarkably impacting on other properties. This suggests the possibility of preparing performing composites by a solvent‐free and easily scalable technique (i.e., melt blending) and obtaining suitable dielectric characteristics, very important for application of such kind of materials, just by tuning the molding conditions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48871.

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Processing‐structure–property relationships in the fabrication of extrusion electroactive poly(vinylidenefluoride) filaments

Saleh

Melenka

Leung

2023

J of Applied Polymer Sci

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Poly(vinylidenefluoride) with enhanced electroactive properties is of great interest in energy harvesting and sensing applications. This study aims to elucidate the effects of processing parameters in extrusion, using a desktop extruder or a microcompounder, on the polymorphism of the fabricated poly(vinylidenefluoride) filaments. All samples were characterized by differential scanning calorimetry, Fourier‐transform infrared spectroscopy, and electromechanical testing. Statistical analyses were conducted to correlate the processing parameters with the poly(vinylidenefluoride) filaments' crystal structures. Experimental results revealed that the optimal extrusion temperature at 220°C and stretching ratio of 4.5 to 6.5 would yield poly(vinylidenefluoride) filaments with a degree of crystallinity of up to 58% of which 80% is β‐phase crystals. The finding of this manuscript has the potential to promote the use of poly(vinylidenefluoride) filaments in the fused filament fabrication.

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Effect of electron irradiation on electroactive phase and dielectric properties of PVDF films

Cited by 19 publications

References 38 publications

Characteristics of PVDF Membranes Irradiated by Electron Beam

Characteristics of PVDF Membranes Irradiated by Electron Beam

PVDF‐based composites containing PZT particles: How processing affects the final properties

Processing‐structure–property relationships in the fabrication of extrusion electroactive poly(vinylidenefluoride) filaments

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