scholarly journals A Review of Piezoelectric PVDF Film by Electrospinning and Its Applications

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5214
Author(s):  
Gulnur Kalimuldina ◽  
Nursultan Turdakyn ◽  
Ingkar Abay ◽  
Alisher Medeubayev ◽  
Arailym Nurpeissova ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Performance Enhancement ◽  
Solution Concentration ◽  
Pvdf Film ◽  
Simple Method ◽  
Preparation Conditions ◽  
Β Phase ◽  
And Performance ◽  
Mechanical Stretching ◽  
Selection Of

With the increase of interest in the application of piezoelectric polyvinylidene fluoride (PVDF) in nanogenerators (NGs), sensors, and microdevices, the most efficient and suitable methods of their synthesis are being pursued. Electrospinning is an effective method to prepare higher content β-phase PVDF nanofiber films without additional high voltage poling or mechanical stretching, and thus, it is considered an economically viable and relatively simple method. This work discusses the parameters affecting the preparation of the desired phase of the PVDF film with a higher electrical output. The design and selection of optimum preparation conditions such as solution concentration, solvents, the molecular weight of PVDF, and others lead to electrical properties and performance enhancement in the NG, sensor, and other applications. Additionally, the effect of the nanoparticle additives that showed efficient improvements in the PVDF films was discussed as well. For instance, additives of BaTiO3, carbon nanotubes, graphene, nanoclays, and others are summarized to show their contributions to the higher piezo response in the electrospun PVDF. The recently reported applications of electrospun PVDF films are also analyzed in this review paper.

scholarly journals Using Annealing Treatment on Fabrication Ionic Liquid-Based PVDF Films

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Yung Ting ◽  
Suprapto ◽  
Naveen Bunekar ◽  
Kulandaivel Sivasankar ◽  
Yopan Rahmad Aldori
Keyword(s):  
Ionic Liquid ◽  
Annealing Treatment ◽  
Amorphous Region ◽  
Hot Water ◽  
Degree Of Crystallinity ◽  
Pvdf Film ◽  
Simple Method ◽  
Strong Electrostatic Interaction ◽  
Β Phase ◽  
And Performance

In this study, a simple method to obtain pure β-phase directly from the melt process is proposed. A series of PVDF and ionic liquid (IL) was prepared by a solvent casting method with appropriate associated with the subsequent annealing treatment. IL plays a role of filler, which can create strong electrostatic interaction with PVDF matrix and directly induce β-phase crystallization on the PVDF during the melt. PVDF film sample is immersed in hot water for annealing treatment at different temperatures (25 °C to 70 °C). We found that annealing in high temperatures especially can not only increase more IL inserted into the amorphous region of polymer matrix to make more phase transformation, but also accelerate IL removal. Characteristics and performance of the PVDF films were investigated by use of FTIR, XRD, SEM, and AFM. Piezoelectric coefficient d33 as well as d31, degree of crystallinity, and sensitivity are measured in experiment to verify the performance of PVDF film.

Piezoelectric PVDF Nanofibrous Membrane Electrospinning Optimization Parameters

2021 ◽  
Vol 897 ◽  
pp. 71-76
Author(s):  
Aliaa Essam ◽  
Ahmed H. El-Shazly ◽  
Hassan Shokry
Keyword(s):  
Flow Rate ◽  
Efficient Method ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Solution Concentration ◽  
Phase Content ◽  
Optimum Conditions ◽  
Β Phase ◽  
Optimization Parameters ◽  
Mechanical Stretching

The application of piezoelectric polyvinylidene fluoride (PVDF) has become of a great interest. Due to its piezoelectric properties, PVDF is used in various applications, namely, microdevices and sensors. Electrospinning was found to be the most suitable and efficient method to synthesis PVDF nanofibers. It is used to obtain PVDF nanofibers without additional mechanical stretching and with high β phase content. For these reasons, it is considered to be an economic technique. In the present paper, the parameters affecting the synthesis of PVDF nanofibers such as solution concentration, flow rate, voltage and Tip to Collector Distance (TCD), have been investigated. The optimum conditions were found to be 18% concentration, 15 cm TCD, 1 mL/h flowrate and 19 kV voltages. The fabricated nanofiber has been characterized using SEM, FTIR, XRD and a conductivity test.

scholarly journals Effect of fabrication technique on the crystalline phase and electrical properties of PVDF films

2015 ◽  
Vol 33 (1) ◽  
pp. 157-162 ◽  
Author(s):  
P. K. Mahato ◽  
A. Seal ◽  
S. Garain ◽  
S. Sen
Keyword(s):  
Polyvinylidene Fluoride ◽  
Tape Casting ◽  
Dimethyl Formamide ◽  
Pvdf Film ◽  
X Ray Diffraction ◽  
Β Phase ◽  
Cast Films ◽  
Solvent Cast ◽  
Ft Ir ◽  
Ferroelectric Hysteresis

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.

Heartbeat Monitoring Technique Based on Corona-Poled PVDF Film Sensor for Smart Apparel Application

2007 ◽  
Vol 124-126 ◽  
pp. 299-302 ◽  
Author(s):  
You Min Chang ◽  
Jong Soon Lee ◽  
Kap Jin Kim
Keyword(s):  
Electric Field ◽  
Polyvinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Computer Applications ◽  
Polymer Materials ◽  
Pvdf Film ◽  
Internal Electric Field ◽  
Film Sensor ◽  
Β Phase ◽  
Voltage Amplifier

Flexible piezoelectric polymer materials for smart apparel and wearable computer applications are of great interest. Among known ferroelectric and piezoelectric polymers, polyvinylidene fluoride (PVDF) exhibit β-phase under poling and is known to give highest piezo-, pyro-, and ferroelectric properties. Previous reports suggests that, during corona poling of the PVDF film, a high surface electric potential is generated resulting in a high internal electric field within the polymer film causing the polarization of the dipoles along the direction of the applied electric field. The resultant phase change from α- to β-phase and the dipole switching generates displacement of charges or piezoelectricity. And also mechanical variation would change dipole density of PVDF film. In this report, we measured human heartbeat signal from an DAQ interfaced with a custommade voltage-amplifier with specific frequency filtering function using the corona-poled PVDF film of various sizes and thickness as a piezoelectric sensor and analyzed it. We employed elastic textile band to sensor system for comfortable fit on wrist or ankle. And then, we found the feasibility of applying flexible PVDF film sensor to smart apparel application which can sense heartbeat rate, blood pressure, respiration rate, accidental external impact on human body, etc.

Designing of a Twin Tube Shock Absorber

2018 ◽  
pp. 83-104 ◽  
Author(s):  
Dheeman Bhuyan
Keyword(s):  
Reverse Engineering ◽  
Shock Absorber ◽  
Performance Enhancement ◽  
Development Stage ◽  
Cad Model ◽  
3D Cad ◽  
Piston Valve ◽  
And Performance ◽  
The One ◽  
Selection Of

Reverse engineering has become the one of the most relevant concepts in modern design doctrines. Advances in technology demand shorter lead time in the overall product development stage, especially in the automobile sector. Hence as a study in reverse engineering, the author has reverse engineered a twin tube shock absorber. The process involved the obtaining of subassemblies of the damper mechanism to generate a 3D CAD model of the damper in PTC CREO 2.0. The model was used to conduct static structural and CFD analysis of the same using ANSYS 15.0 Workbench. The data obtained was used as the datum for the design modifications and performance enhancement of the part. It was seen that the design of the piston valve was optimum hence modifications to the base valve were done. Following the generation of the datum, similar analyses were conducted on the modified assemblies. The results were compared to the datum for the selection of the most appropriate design. Four designs are analyzed and compared with the datum and the set with four orifices in the valve disk was found to be optimum.

Effects of polyvinylidene fluoride sealing on micro-arc oxidation coating of 7075 aluminum alloy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J. Li ◽  
R.G. Song ◽  
X. Qi ◽  
C. Wang ◽  
B. Jiang
Keyword(s):  
Aluminum Alloy ◽  
Polyvinylidene Fluoride ◽  
Microarc Oxidation ◽  
Pvdf Film ◽  
7075 Aluminum Alloy ◽  
Alloy Matrix ◽  
Content Type ◽  
Micro Arc Oxidation ◽  
Oxidation Technology ◽  
And Performance

Purpose The purpose of this is to study the effects of organic sealing on the structure and performance of the micro-arc oxidation (MAO) film of 7075 aluminum alloy. Design/methodology/approach The 7075 aluminum alloy was treated by micro-arc oxidation technology, then the MAO films were sealed by polyvinylidene fluoride (PVDF) solutions with different concentrations to forms a MAO/PVDF composite coating on the surface of the 7075 aluminum alloy matrix. Findings The results show that the MAO/PVDF film thickness increased to 24.8 um. When the PVDF concentration was 8 g/L, and the sealed film reached best corrosion resistance and wear resistance. Originality/value The effects of different concentrations of PVDF on microarc oxidation properties of 7075 aluminum alloy were studied.

scholarly journals Sub-Gram In-Plane Vibration-Driven Robot with Inclined Legs

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 7
Author(s):  
David Robles-Cuenca ◽  
Víctor Ruiz-Díez ◽  
José Luis Sánchez-Rojas ◽  
Jorge Hernando-García
Keyword(s):  
Polyvinylidene Fluoride ◽  
Pvdf Film ◽  
Plane Vibration ◽  
Flexible Materials ◽  
3D Printed ◽  
And Performance ◽  
Robot Platform

This document reports the design, fabrication and performance of miniaturized locomotion systems employing flexible materials and 3D printed legs. The movement of the system was achieved by the first extensional mode of vibration of the platform of the robot and the inclination of the supporting legs. The structures were manufactured using a 30-mm-long piezoelectric polyvinylidene fluoride (PVDF) film as the robot platform, with manually added legs fabricated by stereolithography (SLA). Several speed measurements were performed for samples of 1- and 2-mm-long legs, at an angle of inclination of 45° and 60° to the PVDF film. The system was able to exceed a speed of 1 BL/s (body-lengths per second) to 25 V.

Loop Heat Pipe Design: An Evaluation of Recent Research on the Selection of Evaporator, Wick and Working Fluid

2021 ◽  
pp. 1-32
Author(s):  
Shahnawaz Ahmed ◽  
Manmohan Pandey ◽  
Masahiro Kawaji
Keyword(s):  
Heat Pipe ◽  
Performance Enhancement ◽  
Special Section ◽  
Design Guidelines ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Figures Of Merit ◽  
Thin Film Evaporation ◽  
And Performance ◽  
Selection Of

Abstract Since its invention nearly five decades ago, the loop heat pipe has revolutionized every application requiring cooling or maintaining a constant temperature environment. In this article, its various designs aspects are explored, which include design of the evaporator, wick and selection of working fluid. Factors such as design guidelines and how they affect the physics of the overall system are surveyed. For the evaporator part, its various designs and their respective applications/operating ranges are reviewed. In the wick section, recent trends on its fabrication, and performance enhancement are shown. A special section on how the wick functions is added, with a focus on the study of liquid vapour meniscus using the thin-film evaporation theory. Attention is also given to the investigations on the various figures of merit used for the selection of working fluid. For the first time, these figures of merit are categorized with respect to the device physics they represent/simulate. In the end, this review article also touches upon the various creative designs and ideas used to enhance the loop heat pipe performance.

scholarly journals Preparation, Structure and Properties of Acid Aqueous Solution Plasticized Thermoplastic Chitosan

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 818 ◽  
Author(s):  
Yu Zhang ◽  
Biao-Lan Liu ◽  
Liang-Jie Wang ◽  
Ying-Hua Deng ◽  
Shi-Yi Zhou ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Solution Concentration ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Characterization Methods ◽  
Modified Chitosan ◽  
Acid Aqueous Solution ◽  
And Performance

This work provides a simple method for the preparation of thermoplastic chitosan using the most common dilute inorganic and organic acids in aqueous solutions, namely hydrochloric acid (HCl) and acetic acid (HAc). The melting plasticization behavior of chitosan under different concentrations and types of acid solution was investigated. By means of infrared spectra (IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and other characterization methods, as well as a mechanical property test, it was found that as the acid solution concentration increased, the protonation effect was stronger and the plasticization performance showed a better trend. The structure and performance of the modified chitosan were optimal when the concentration of HCl was around 8 wt %. In addition, it was found that HCl had a better effect on the plasticization of chitosan than HAc, which was because the protonation ability of HCl was stronger than that of HAc. Unlike the casting method, the structure and properties of chitosan sheets prepared by thermoplastic processing were directly affected by protonation, however not by the interaction of anionic-cationic electrostatic attractions between the –NH3+ groups of chitosan chains and the carboxyl groups of acetic acids or the chloridoid groups of hydrochloric acid.

Properties of PVDF films stretched in machine direction

2020 ◽  
pp. 096739112091059
Author(s):  
TS Roopa ◽  
HN Narasimha Murthy ◽  
DVN Harish ◽  
Anjana Jain ◽  
Gangadhar Angadi
Keyword(s):  
Electron Microscopy ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Gray Relational Analysis ◽  
X Ray Diffraction ◽  
Polar Solvents ◽  
Β Phase ◽  
Transmission Electron ◽  
Diffraction Peaks ◽  
Mechanical Stretching

Polyvinylidene fluoride (PVDF) films possess superior piezoelectric properties due to the β-phase obtained by methods, such as addition of nanofillers, application of high electric field, use of polar solvents and mechanical stretching. Simultaneous stretching and heating of the films can reduce porosity, increase transformation from α-phase to β-phase, and hence, improve their piezoelectric properties. This article presents the effects of stretching PVDF films on the β-phase formation and the resulting mechanical properties. A custom-designed stretching unit with roller mechanism and heating provision was employed for the purpose. The 200% stretched films at 100°C showed 86.79% β-phase, which is in correlation with X-ray diffraction peaks at 2 θ = 20.3–20.6°. Transmission electron microscopy and scanning electron microscopy of the stretched films revealed spherulitic to lamellar transformation and decrease in porosity. Stretching increased crystallinity from 32.99% to 44.84%. Nanoindentation results showed increase in hardness and Young’s modulus from 23.33 MPa to 93.3 MPa and 0.483 GPa to 1.816 GPa, respectively. Tensile strength increased from 4.72 MPa to 21.02 MPa. The experiments were conducted using L9 orthogonal array and the results were analyzed using analysis of variance and gray relational analysis.

Sign in / Sign up

Export Citation Format

Share Document