Enhancement of dielectric permittivity and ferroelectricity of a modified cobalt nanoparticle and polyvinylidene fluoride based composite

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8591-8597 ◽  
Author(s):  
K. Vasundhara ◽  
B. P. Mandal ◽  
A. K. Tyagi
Keyword(s):  
Dielectric Constant ◽  
Dielectric Permittivity ◽  
Polyvinylidene Fluoride ◽  
Cobalt Nanoparticles ◽  
Remarkable Increase ◽  
Β Phase ◽  
Pvdf Matrix ◽  
Cobalt Nanoparticle

A remarkable increase in the amount of polar β phase has been observed upon dispersion of cobalt nanoparticles in the PVDF matrix. A significant improvement in the dielectric constant of PVDF has been achieved.

scholarly journals Enhanced Piezoelectric Behavior of PVDF Nanocomposite by AC Dielectrophoresis Alignment of ZnO Nanowires

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Kyungwho Choi ◽  
Woongchul Choi ◽  
Choongho Yu ◽  
Yong Tae Park
Keyword(s):  
Dielectric Constant ◽  
Polymer Matrix ◽  
Polyvinylidene Fluoride ◽  
Zno Nanowires ◽  
Lead Free ◽  
Poling Process ◽  
Piezoelectric Polymer ◽  
The Matrix ◽  
Pvdf Matrix ◽  
Piezoelectric Behavior

In contrast to commercial piezoelectric ceramics, lead-free materials such as ZnO and a polymer matrix are proper candidates for use in ecofriendly applications. In this article, the authors represent a technique using ZnO nanowires with a polyvinylidene fluoride (PVDF) matrix in a piezoelectric polymer composite. By aligning the nanowires in the matrix in a desired direction by AC dielectrophoresis, the piezoelectric behavior was enhanced. The dielectric constant of the composite was improved by increasing the concentration of the ZnO nanowires as well. Specifically, the resulting dielectric constant shows an improvement of 400% with aligned ZnO nanowires by increasing the poling effect compared to that of a randomly oriented nanowire composite without a poling process.

High dielectric permittivity and low loss of polyvinylidene fluoride filled with carbon additives: Expanded graphite versus reduced graphene oxide

2018 ◽  
Vol 31 (7) ◽  
pp. 778-784
Author(s):  
Wei Deng ◽  
Weili Yu ◽  
Weiwei Cui ◽  
Huachao Guo ◽  
Yifan Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Dielectric Loss ◽  
Dielectric Permittivity ◽  
Reduced Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Expanded Graphite ◽  
High Dielectric Permittivity ◽  
Reduced Graphene ◽  
Pvdf Matrix ◽  
High Dielectric

Polymer dielectric composites with high dielectric permittivity and low dielectric loss play an increasing important role for modern electronic and electric industry. In this study, polyvinylidene fluoride (PVDF) incorporated with expanded graphite (EG) or reduced graphene oxide (rGO) was prepared by solution casting and the following hot pressing. The structure, morphology, and properties of the obtained products were characterized. In comparison with EG, rGO exhibits well dispersion and strong interaction with PVDF matrix. With the increasing content of conductive fillers, the dielectric permittivity of both PVDF/EG and PVDF/rGO composites shows an increasing trend whereas the dielectric loss keeps at a low level. The dielectric permittivity of PVDF filled with 4 wt% EG and 8 wt% rGO reaches 420 and 38 at 100 Hz, respectively. Moreover, the introduction of EG and rGO improves the mechanical strength and the thermal stability of PVDF matrix.

Preparation of TiO2 Polymer Nanodielectrics via a Solvent-Based Technique

2010 ◽  
Author(s):  
Payam Khodaparast ◽  
Zoubeida Ounaies
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Thermal Annealing ◽  
High Dielectric Constant ◽  
Maxwell Model ◽  
Nanocomposite Films ◽  
Pvdf Matrix ◽  
High Dielectric ◽  
Considerable Enhancement

The effect of adding surface-functionally treated TiO2 nanoparticles on dielectric properties of PVDF matrix was investigated. Porosity of the nanocomposite films showed to have an impact on dielectric permittivity results. Thermal annealing was proposed as an effective way to overcome the porosity problem. By combination of surface treatment of particles and thermal annealing of nanocomposite films, considerable enhancement in dielectric permittivity of TiO2-PVDF nanocomposites was achieved. The experimental results were far higher than theoretical values based on Maxwell model, indicating the presence of an active interphase with high dielectric constant in the system.

Nanostructures and dielectric properties of PVDF-based polymer films with high energy density and low energy losses

2015 ◽  
Vol 1740 ◽  
Author(s):  
Masahiko Ando ◽  
Naoki Yoshimoto ◽  
Yuichiro Yoshitake ◽  
Shuji Kato ◽  
Hidekazu Kodama ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Polymer Films ◽  
Polyvinylidene Fluoride ◽  
High Dielectric Constant ◽  
Electrical Energy ◽  
High Energy ◽  
High Energy Density ◽  
Β Phase ◽  
High Dielectric

ABSTRACTBased on the investigation of mechanism for large dielectric losses in relaxor fluorinated polymers, polyvinylidene fluoride (PVDF) derivatives, a new nanostructure-controlled PVDF based polymer films with low dielectric loss, tanδ < 1% (0.6%), and high dielectric constant, εr = 13 at frequency of 1 kHz, was proposed for electrical energy storage applications. The high dielectric loss was mainly due to the electric-field induced α-β phase transition, and one dimensional extension of P(VDF-TrFE)-g-PEMA films was found to reduce the α phase component resulting in reduction of the dielectric loss while keeping the high dielectric constant. In-situ FTIR measurements suggested a possibility of further reducing the dielectric-loss.

Fabrication of Piezoelectric Polyvinylidene Fluoride (PVDF) Polymer-Based Tactile Sensor Using Electrospinning Method

2016 ◽  
Vol 12 ◽  
pp. 42-50 ◽  
Author(s):  
N. Manikandan ◽  
S. Muruganand ◽  
K. Sriram ◽  
P. Balakrishnan ◽  
A. Suresh Kumar
Keyword(s):  
Polyvinylidene Fluoride ◽  
Biomedical Application ◽  
Electric Pulse ◽  
High Sensitivity ◽  
Tactile Sensor ◽  
Main Role ◽  
Nano Structure ◽  
Sem Image ◽  
Β Phase ◽  
Α Phase

The polyvinylidene fluoride (PVDF) nanofiber has widely investigated as a sensor and transducer material, because of its high piezo and Ferro electric properties. The novel nano structure of PVDF has attracted considerable interest in the bio sensing and biomedical application. This paper deals with PVDF Tactile sensor. Basically The PVDF acts as piezoelectric effect which convert load into electrical signals. The tactile sensor has a main role for visual handicap and robotics. Any physical activities of robotic in all industrial the tactile sensor is a crucible role, whether it can left the object or handling glass parts pressure of object is main. The Sandwich type PVDF base tactile sensor has been fabricated using nanofiber. Using electro spinning method, the PVDF based nanofiber coated over coper the electrodes. In normal, the PVDF has α-phase and while applying electric pulse the PVDF polymer would be changed from α-phase into β-phase. Only in β-phase, the PVDF act as piezo electrics sensor and measure the piezoelectricity simultaneously measure pressure and temperature in real time. The pressure was monitored from the change in the electrical resistance via the piezo resistance of the material. The enhancement of PVDF properties has been carried by using SEM. The SEM image result showed that the size of nanofiber, the size of nanofiber is varied in the range of (180 nm-400 nm) with smooth surface. The X-Ray diffraction has shown that the PVDF was aggregated with the β-phase crystalline nature. Due to β-phase it was act as a piezo electric prosperity’s and its results are very high sensitivity.

scholarly journals Electrospun Polyvinylidene Fluoride-Based Fibrous Scaffolds with Piezoelectric Characteristics for Bone and Neural Tissue Engineering

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 952 ◽  
Author(s):  
Li ◽  
Liao ◽  
Tjong
Keyword(s):  
Tissue Engineering ◽  
Polyvinylidene Fluoride ◽  
Neural Tissue ◽  
Electrospinning Process ◽  
Neural Cells ◽  
Neural Tissue Engineering ◽  
Engineering Applications ◽  
Pore Sizes ◽  
Β Phase ◽  
Small Pore

Polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE) with excellent piezoelectricity and good biocompatibility are attractive materials for making functional scaffolds for bone and neural tissue engineering applications. Electrospun PVDF and P(VDF-TrFE) scaffolds can produce electrical charges during mechanical deformation, which can provide necessary stimulation for repairing bone defects and damaged nerve cells. As such, these fibrous mats promote the adhesion, proliferation and differentiation of bone and neural cells on their surfaces. Furthermore, aligned PVDF and P(VDF-TrFE) fibrous mats can enhance neurite growth along the fiber orientation direction. These beneficial effects derive from the formation of electroactive, polar β-phase having piezoelectric properties. Polar β-phase can be induced in the PVDF fibers as a result of the polymer jet stretching and electrical poling during electrospinning. Moreover, the incorporation of TrFE monomer into PVDF can stabilize the β-phase without mechanical stretching or electrical poling. The main drawbacks of electrospinning process for making piezoelectric PVDF-based scaffolds are their small pore sizes and the use of highly toxic organic solvents. The small pore sizes prevent the infiltration of bone and neuronal cells into the scaffolds, leading to the formation of a single cell layer on the scaffold surfaces. Accordingly, modified electrospinning methods such as melt-electrospinning and near-field electrospinning have been explored by the researchers to tackle this issue. This article reviews recent development strategies, achievements and major challenges of electrospun PVDF and P(VDF-TrFE) scaffolds for tissue engineering applications.

scholarly journals Estimation of S-parameters and dielectric permittivity of quartz ceramics samples in millimeter waveband

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 65-71
Author(s):  
N. A. Pevneva ◽  
D. A. Kondrashov ◽  
A. L. Gurskii ◽  
A. V. Gusinsky
Keyword(s):  
Dielectric Constant ◽  
Dielectric Permittivity ◽  
Ceramic Materials ◽  
Reflection And Transmission Coefficients ◽  
Frequency Range ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Higher Order Modes ◽  
S Parameters ◽  
The Fourier Transform

A modified Nicholson – Ross – Weir method was used to determine complex parameters and dielectric permittivity of ceramic materials in the range 78.33–118.1 GHz. The measuring equipment is a meter of complex reflection and transmission coefficients, a waveguide measuring canal with a special measuring cell, consisting of two irregular waveguides and a waveguide chamber between them, which provides insignificant influence of higher-order modes. The dependences of the amplitude and phase of the reflection and transmission coefficients on frequency were obtained experimentally for fluoroplastic and three ceramic samples in the frequency range 78.33–118.1 GHz. The obtained S-parameters are processed according to an algorithm that includes their averaging based on the Fourier transform in order to obtain the values of the dielectric permittivity. Fluoroplastic was used as a reference material with a known dielectric constant. The dielectric constant of fluoroplastic has a stable value of 2.1 in the above mentioned frequency range. The dielectric constant of sample No. 1 varies from 3.6 to 2.5 at the boundaries of the range, sample No. 2 – from 3.7 to 2.1, sample No. 3 – from 2.9 to 1.5. The experimental data are in satisfactory agreement with the literature data for other frequencies taking into account the limits set by the measurement uncertainty.

scholarly journals Piezoelectric Properties of Zinc Oxide/Iron Oxide filled Polyvinylidene fluoride Nanocomposite Fibers

2021 ◽  
Author(s):  
Abdulrahman Mohmmed AlAhzm ◽  
Maan Omar Alejli ◽  
Deepalekshmi Ponnamma ◽  
Yara Elgawady ◽  
Mariam Al Ali Al-Maadeed
Keyword(s):  
Zinc Oxide ◽  
Iron Oxide ◽  
Polyvinylidene Fluoride ◽  
Output Voltage ◽  
Mechanical Energy ◽  
Scanning Calorimetry ◽  
Power Sources ◽  
Hybrid Nanomaterial ◽  
Β Phase ◽  
Nanocomposite Fibers

Abstract Piezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun nanocomposite fibers from polyvinylidene fluoride (PVDF) filled Zinc Oxide (ZnO)/Iron Oxide (FeO) nanomaterials. The nanocomposite fiber based flexible PENG showed piezoelectric output voltage of 5.9 V when 3 wt.% of ZnO/FeO hybrid nanomaterial was introduced, which was 29.5 times higher than the neat PVDF. No apparent decline in output voltage was observed for almost 2000 seconds attributed to the outstanding durability. This higher piezoelectric output performance is correlated with the β-phase transformation studies from the Fourier transformation infrared spectroscopy and the crystallinity studies from the differential scanning calorimetry. Both these studies show respective enhancement of 3.79 and 2.16 % in the β-phase crystallinity values of PVDF-ZnO/FeO 3 wt.% composite. Higher dielectric constant value obtained for the same composite (3 times higher than the neat PVDF) confirms the increased energy storage efficiency as well. Thus the proposed soft and flexible PENG is a promising mechanical energy harvester, and its good dielectric properties reveals the ability to use this material as good power sources for wearable and flexible electronic devices.

Low loss high dielectric permittivity of polyvinylidene fluoride and KxTiyNi1−x−yO (x=0.05, y=0.02) composites

2010 ◽  
Vol 107 (12) ◽  
pp. 124115 ◽  
Author(s):  
Debabrata Bhadra ◽  
A. Biswas ◽  
S. Sarkar ◽  
B. K. Chaudhuri ◽  
K. F. Tseng ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Polyvinylidene Fluoride ◽  
Low Loss ◽  
High Dielectric Permittivity ◽  
High Dielectric
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