Polyvinylidene fluoride nanofibers obtained by electrospinning and blowspinning: Electrospinning enhances the piezoelectric β‐phase – myth or reality?

2020 ◽  
Vol 138 (10) ◽  
pp. 49959
Author(s):  
Cherif M. Azzaz ◽  
Luiz H. C. Mattoso ◽  
Nicole R. Demarquette ◽  
Ricardo J. Zednik
2016 ◽  
Vol 12 ◽  
pp. 42-50 ◽  
Author(s):  
N. Manikandan ◽  
S. Muruganand ◽  
K. Sriram ◽  
P. Balakrishnan ◽  
A. Suresh Kumar

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.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 952 ◽  
Author(s):  
Li ◽  
Liao ◽  
Tjong

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.


2021 ◽  
Author(s):  
Abdulrahman Mohmmed AlAhzm ◽  
Maan Omar Alejli ◽  
Deepalekshmi Ponnamma ◽  
Yara Elgawady ◽  
Mariam Al Ali Al-Maadeed

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.


2015 ◽  
Vol 33 (1) ◽  
pp. 157-162 ◽  
Author(s):  
P. K. Mahato ◽  
A. Seal ◽  
S. Garain ◽  
S. Sen

AbstractThe effect of different fabrication techniques on the formation of electroactive β-phase polyvinylidene fluoride (PVDF) has been investigated. Films with varying concentration of PVDF and solvent - dimethyl formamide (DMF) were synthesized by tape casting and solvent casting techniques. The piezoelectric β-phase as well as non polar β-phase were observed for both the tape cast and solvent cast films from X-ray diffraction (XRD) micrographs and Fourier transform infra-red spectroscopy (FT-IR) spectra. A maximum percentage (80 %) of β-phase was obtained from FT-IR analysis for a solvent cast PVDF film. The surface morphology of the PVDF films was analyzed by FESEM imaging. The dielectric properties as a function of temperature and frequency and the ferroelectric hysteresis loop as a function of voltage were measured. An enhancement in the value of the dielectric constant and polarization was obtained in solvent cast films.


2019 ◽  
Vol 851 ◽  
pp. 113417 ◽  
Author(s):  
Rupali Singh ◽  
S. Janakiraman ◽  
Mohammed Khalifa ◽  
S. Anandhan ◽  
Sudipto Ghosh ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8591-8597 ◽  
Author(s):  
K. Vasundhara ◽  
B. P. Mandal ◽  
A. K. Tyagi

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.


2012 ◽  
Vol 566 ◽  
pp. 462-465 ◽  
Author(s):  
Zong Hsin Liu ◽  
Li Wei Lin ◽  
Cheng Teng Pan ◽  
Zong Yu Ou

In this study, near-field electrospining on hollow cylindrical (NFES) process was used to fabricate permanent piezoelectricity of polyvinylidene fluoride (PVDF) piezoelectric nanofibers. With in situ electric poling, mechanical stretching and heating during NFES process, the pre-strained piezoelectric PVDF nanofibers with high stretchability and energy conversion efficiency can be applied at low-frequency ambient vibration to convert mechanical energies into electrical signals. By adjusting rotating velocity of the hollow cylindrical glass tube on X-Y stage, electric field, baking temperature and carbon nanotube (CNT) concentration in PVDF solution, the crystalline of β phase, polarization intensity and morphology of piezoelectric fiber can be controlled. XRD (X-ray diffraction) observation of PVDF fibers was characterized. With electric field 0.5×107 V/m (needle-to-tube distance 2 mm and DC voltage 5 kV), rotating velocity 400 r.p.m, baking temperature 80 °C and 0.03 wt% CNT in NFES process, it reveals a high diffraction peak at 2θ=20.8° of piezoelectric crystal β-phase structure. Then the array nanofibers were transferred onto a parallel copper electrode by using flexible insulation epoxy/PI film to provide packaging protection. When the sensor was tested under 5 Hz vibration frequency, the maximum induced voltage was 29.4 mVp-p.


2020 ◽  
pp. 0021955X2094566
Author(s):  
Yu-Chen Sun ◽  
Jennifer D’Cunha ◽  
Hani E Naguib

A novel nanocomposite foam with microcellular structures based on poly(vinylidene fluoride) (PVDF) and titanium dioxide (TiO2) was fabricated by the combination of melt compounding and supercritical carbon dioxide (scCO2) foaming. To improve its dielectric performance, silane modified and unmodified titanium dioxide nanoparticles were added as reinforcing fillers at low weight percentages (0.5, 1, and 5 wt%) during the melt blending process. It was found that the incorporation of nanoparticles had a strong influence on cell morphology. As a result, the foaming process significantly altered the dielectric, and mechanical properties of the composite foams. The dielectric constants of the composite foams were no longer frequency dependent while tan delta was lowered at least by a factor of 10. Furthermore, the porous structure generated by foaming also assisted the α-to-β phase transformation of the PVDF matrix in a way similar to mechanical stretching. Such method is superior to other phase transformation techniques since β-phase PVDF can be produced in bulk geometries instead of a thin film configuration.


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