scholarly journals Development of poly (vinylidene fluoride)/silver nanoparticle electrospun nanofibre mats for energy harvesting

2021 ◽  
pp. 096739112110420
Author(s):  
Roopa Thotadara Shivalingappa ◽  
Hebbale Narayana Rao Narasimha Murthy ◽  
Pradeep Purushothaman ◽  
Prasanna Badiger ◽  
Swapnil Savarn ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Applied Pressure ◽  
Fibre Diameter ◽  
X Ray Diffraction ◽  
Β Phase ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Poly Vinylidene Fluoride

Energy harvesting using piezoelectric materials finds attention of researchers due to miniaturisation. Polyvinylidene fluoride (PVDF) is one such polymeric material with high piezoelectric and pyroelectric properties and hence is used for sensors, actuators, energy harvesting and biomedical devices. This study reports electrospinning of PVDF/Ag nanoparticles (AgNP) nanofibre mats for energy harvesting. Nanofibre mats were prepared by adopting voltage (20 kV), flow rate (1.5 mL/hour) and tip to collector distance (19 cm). The fibre mats were characterised using Fourier-Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). FTIR and XRD results showed 11.84% and 36.36% increase in β-phase and crystallinity, respectively, due to the addition of 1.5 wt. % AgNP to PVDF. SEM micrographs showed decrease in bead formation and increase in fibre diameter from 40 nm to 355 nm due to the addition of AgNP. Sensitivity and voltage output were studied. The fibre mats were used for development of a miniature burglar alarm system, and its response to the applied pressure was tested.

Comparative study on the dielectric properties of three polyvinylidene fluoride nanocomposites incorporated with carbon filler

2017 ◽  
Vol 31 (8) ◽  
pp. 1102-1111 ◽  
Author(s):  
Dandan Yang ◽  
Haiping Xu ◽  
Wei Yu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Hot Press ◽  
X Ray Diffraction ◽  
Carbon Filler ◽  
Solution Blending ◽  
Β Phase ◽  
Pristine Cnts ◽  
Poly Vinylidene Fluoride ◽  
Press Method

Poly(vinylidene fluoride) (PVDF)-carbon nanotube (CNT) composites with three different CNTs were prepared by a solution blending and hot-press method. The morphologies of nanocomposites were studied by scanning electron microscopy. The X-ray diffraction and differential scanning calorimeter data indicated that the addition of CNTs can promote the formation of β-phase of PVDF. The dielectric constant values of three PVDF/CNTs are much greater than that of neat PVDF. It has been found that the dielectric loss of the short hydroxylated CNTs filled PVDF nanocomposite is lower than those of other two long pristine CNTs filled PVDF nanocomposites.

Role of Cationic Oxidation States to Enhance the Electroactive β-Phase of Poly(vinylidene Fluoride) and its Energy Harvesting Performance

2018 ◽  
Vol 5 (22) ◽  
pp. 3533-3539 ◽  
Author(s):  
Kausalya Ganesan ◽  
Nagamalleswara R. Alluri ◽  
Nirmal Prashanth M. J. Raj ◽  
A. Chandrasekhar ◽  
S.-J. Kim
Keyword(s):  
Energy Harvesting ◽  
Vinylidene Fluoride ◽  
Oxidation States ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

scholarly journals Influence of molecular weight on dielectric properties and piezoelectric constant of poly(vinylidene fluoride) membranes obtained by electrospinning

Polimery ◽  
2021 ◽  
Vol 66 (10) ◽  
pp. 532
Author(s):  
Aminatul Sobirah Zahari ◽  
Muhammad Hafiz Mazwir ◽  
Izan Izwan Misnon
Keyword(s):  
Molecular Weight ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Piezoelectric Constant ◽  
Phase Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

A significant influence of the molecular weight on the dielectric properties and piezoelectric constant of poly(vinylidene fluoride) (PVDF) membranes obtained by electrospinning was demonstrated. Electrochemical impedance spectroscopy and d33 meter were used to evaluate dielectric properties and piezoelectric constant respectively. The presence of the β-phase was determined by Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD). The membranes with the lowest molecular weight (180,000 g/mol) possessed the best dielectric properties. They also had the highest piezoelectric constant (21 pC/N) and dielectric constant (2.9 at 50 Hz) as well as the highest β-phase content (80.25%).

A STUDY ON THERMO-OPTIC EFFECT OF β POLY(VINYLIDENE FLUORIDE) THIN FILMS PREPARED BY SOLUTION CASTING METHOD

2008 ◽  
Vol 15 (01n02) ◽  
pp. 175-181 ◽  
Author(s):  
YINGXUE XI ◽  
HUIQING FAN ◽  
WEIGUO LIU ◽  
CHEN YANG ◽  
XIAOLING NIU
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Infrared Imaging ◽  
Vinylidene Fluoride ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Long Wavelength ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Solution Casting Method

The Poly(vinylidene) fluoride (PVDF) thin films with a high content of β-phase were prepared by controlling heat-treatment temperature using casting from the poled solvents. The crystallite microstructure of thin films was depicted by the techniques of X-ray diffraction and FTIR. The results showed that heat treatment was favorable for inducing the β- and γ-phase formation of PVDF. The β phase films were obtained with heat treatment at temperatures ranging from 60°C to 120°C and annealing at 120°C after casting from DMF. The thermo-optical effect of β phase PVDF films was investigated using a spectroscopic ellipsometer. At temperatures ranging from 20°C to 100°C, the refractive index of PVDF was negatively correlated with the temperature between 350 and 1500 nm. The value of the t.o. coefficient of PVDF films was calculated at all temperatures. The maximum value of the t.o. coefficient was about 3.3 × 10-4/°C at the ascending stage of temperature and 3.0 × 10-4/°C at the descending stage of temperature. Therefore, it is possible to use the thermo-optic effect of the β phase PVDF for long wavelength infrared imaging.

Stretching Induced Crystalline-Phase Transition in Energy-Conversion Poly(Vinylidene Fluoride) (PVDF) Films

2014 ◽  
Vol 1070-1072 ◽  
pp. 589-593
Author(s):  
Fei Peng Wang ◽  
Zheng Yong Huang ◽  
Jian Li
Keyword(s):  
Phase Transition ◽  
Crystalline Phase ◽  
High Speed ◽  
Vinylidene Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Poly Vinylidene Fluoride ◽  
Crystalline Phase Transition

Commercial poly (vinylidene fluoride) (PVDF) films are uniaxially stretched with varying rates at 110 °C in order to endow PVDF piezo-and pyroelectric by crystalline-phase transition from α to β during the stretching. The crystalline phases are determined by infrared spectroscopy. The β-phase content and its fraction in films increase as a result of stretching with high rates. In addition, higher stretching rates yield a slight increase of γ phase. The crystallite size is evaluated by means of X-ray diffraction. It is found that the β-phase crystallites become smaller with fast stretching, whereas the α-phase crystallites are cracked and disappear at high-speed stretching of 2.5 /min.

scholarly journals Static-Aligned Piezoelectric Poly (Vinylidene Fluoride) Electrospun Nanofibers/MWCNT Composite Membrane: Facile Method

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 965 ◽  
Author(s):  
Nader Shehata ◽  
Eman Elnabawy ◽  
Mohamed Abdelkader ◽  
Ahmed Hassanin ◽  
Mohamed Salah ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Speed ◽  
Vinylidene Fluoride ◽  
Electrospun Nanofibers ◽  
Piezoelectric Response ◽  
Rotating Drum ◽  
Β Phase ◽  
Aligned Nanofibers ◽  
Poly Vinylidene Fluoride ◽  
Nanofiber Mats

Polyvinylidene Fluoride (PVDF) piezoelectric electrospun nanofibers have been intensively used for sensing and actuation applications in the last decade. However, in most cases, random PVDF piezoelectric nanofiber mats have moderate piezoelectric response compared to aligned PVDF nanofibers. In this work, we demonstrate the effect of alignment conducted by a collector setup composed of two-metal bars with gab inside where the aligned fiber can be formed. That is what we called static aligned nanofibers, which is distinct from the dynamic traditional technique using a high speed rotating drum. The two-bar system shows a superior alignment degree for the PVDF nanofibers. Also, the effect of added carbon nanotubes (CNTs) of different concentrations to PVDF nanofibers is studied to observe the enhancement of piezoelectric response of PVDF nanofibers. Improvement of β-phase content of aligned (PVDF) nanofibers, as compared to randomly orientated fibers, is achieved. Significant change in the piezoelectricity of PVDF fiber is produced with added CNTs with saturation response in the case of 0.3 wt % doping of CNTs, and piezoelectric sensitivity of 73.8 mV/g with applied masses down to 100 g.

Structure and electrophysical properties of polyvinylidene fluoride (PVDF)/magnetite nanocomposites

2018 ◽  
Vol 33 (1) ◽  
pp. 138-149 ◽  
Author(s):  
MA Ramazanov ◽  
AM Maharramov ◽  
HA Shirinova ◽  
Luca Di Palma
Keyword(s):  
Dielectric Permittivity ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Theoretical Calculations ◽  
Threshold Value ◽  
Electrophysical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Subsequent Decrease ◽  
Poly Vinylidene Fluoride

In the present study, the effect of magnetite (Fe3O4) nanoparticles on the structural and dielectric properties of poly(vinylidene fluoride) (PVDF) matrix was investigated. Distribution of Fe3O4 nanoparticles in the polymer matrix has been studied by scanning electron microscopy (JEOL JSM-7600 F). The structure of the nanocomposite samples was investigated by the X-ray diffraction and Fourier-transform infrared spectroscopy. It was shown that the dielectric permittivity of PVDF + Fe3O4 nanocomposite samples was gradually increased up to 7 wt% of Fe3O4 content. Further increase in the concentration of the filler leads to decrease in the dielectric permittivity. The subsequent decrease in dielectric permittivity at higher Fe3O4 content can be explained by the increase in defects in the structure of the nanocomposite. The comparison of experimental data and the results of theoretical calculations show that the reduction in the empirical value of dielectric permittivity of the nanocomposite is obviously linked with the threshold value of filler. While calculating the theoretical value of the dielectric permittivity for the higher content of the filler, defects in the nanocomposite structure should be considered.

Phase Transition in Poly(Vinylidene Fluoride) Investigated with Micro-Raman Spectroscopy

2005 ◽  
Vol 59 (3) ◽  
pp. 275-279 ◽  
Author(s):  
C. J. L. Constantino ◽  
A. E. Job ◽  
R. D. Simões ◽  
J. A. Giacometti ◽  
V. Zucolotto ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
Vinylidene Fluoride ◽  
Raman Band ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Β Phase ◽  
Α Phase ◽  
Poly Vinylidene Fluoride

The phase transition from the non-polar α-phase to the polar β-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous because it is a nondestructive technique. Films of α-PVDF were subjected to stretching under controlled rates at 80 °C, while the transition to β-PVDF was monitored by the decrease in the Raman band at 794 cm−1 characteristic of the α-phase, along with the concomitant increase in the 839 cm−1 band characteristic of the β-phase. The α→β transition in our PVDF samples could be achieved even for the sample stretched to twice (2×-stretched) the initial length and it did not depend on the stretching rate in the range between 2.0 and 7.0 mm/min. These conclusions were corroborated by differential scanning calorimetry (DSC) and X-ray diffraction experiments for PVDF samples processed under the same conditions as in the Raman scattering measurements. Poling with negative corona discharge was found to affect the α-PVDF morphology, improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, i.e., X-ray diffraction and infrared spectroscopy.

Electrically excited oscillation and crystalline structure of a nanoclay/poly(vinylidene fluoride) composite film

2011 ◽  
Vol 22 (18) ◽  
pp. 2103-2112 ◽  
Author(s):  
Go Murasawa ◽  
Akihiro Nishioka ◽  
Ken Miyata ◽  
Tomonori Koda ◽  
Hideo Cho
Keyword(s):  
Composite Film ◽  
Crystalline Structure ◽  
Vinylidene Fluoride ◽  
Composite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Impedance Characteristics ◽  
Poly Vinylidene Fluoride ◽  
Excited Oscillation

This study was conducted to investigate electrically excited oscillation and crystalline structure of nanoclay/poly(vinylidene fluoride) (PVDF) composite films. First, nanoclay/PVDF composite films are fabricated by solvent casting. Second, their PVDF crystalline structure and nanoclay orientation are analyzed using x-ray diffraction. The impedance characteristics of films are then measured. Third, the oscillation excited from films as a result of applied voltage is measured. Thereby, we confirmed the presence of unoriented β-phase PVDF crystals and exfoliated-type nanoclay structure in a composite film. The output oscillation showed monotonic component corresponding to the input sinusoidal voltage at a high frequency range, although its amplitude is low.

Sign in / Sign up

Export Citation Format

Share Document