Fabrication, Characterization and Investigation of Novel PVDF/ZnO and PVDF-TrFE/ZnO Nanocomposites with Enhanced β-Phase and Dielectricity

2020 ◽  
Vol 977 ◽  
pp. 277-282
Author(s):  
Ming Ran Liu
Keyword(s):  
Human Body ◽  
Polyvinylidene Fluoride ◽  
Pressure Sensors ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Zno Nanostructure ◽  
Β Phase ◽  
Arterial Blood ◽  
Sensing Material

To date, flexible, sensitive and biocompatible pressure sensors for fluctuation signals in human body have been mainly demonstrated for detecting body and muscle motion, pulse rate, heart rate and arterial blood pressure. However, because of the lack of sufficient sensitivity and flexibility, pulse signals with relatively low intensity cannot be identified and captured, such as signals derived from microcirculation in human body. As confirmed and validated by researchers, once PVDF and its copolymer based nanocomposite sensing material are applied in piezoelectric sensors, its sensitivity and piezoelectricity are highly relevant. Therefore, as one of the most effective methods to improve the permittivity and piezoelectricity of PVDF and its copolymer based nanocomposite, the effect of increasing the content of β-phase crystal was investigated in this work. In this project, the sensor possessing a novel sensing layer with the nanofiller was investigated and fabricated. The proposed sensor was designed in a simple but efficient sandwich structure. The sensing layer of the proposed sensor was made of polyvinylidene fluoride (PVDF) and polyvinylidenefluoride-trifluoroethylene (PVDF-TrFE) based nanocomposite with Zinc Oxide (ZnO) nanostructure acting as a filler portion which was fabricated by the method of Chemical Bath Deposition (CBD). The fabricated nanocomposite sensing layers were characterized. The microstructures and morphologies of pristine PVDF (P), PVDF-TrFE (PT), PVDF/ZnO (P/Z) and PVDF-TrFE/ZnO (PT/Z) with different concentration were characterized by Scanning Electron Microscope (SEM). The degree of crystallinity for P, PT, P/Z and PT/Z was obtained by X-ray Diffraction meter (XRD). In conclusion, PT exhibited better performance in both morphology and crystallinity as a sensing membrane material. More β‐phase in PT was obtained than that in P. ZnO, as a semiconductor filler, would have substantial influence on enhancing the dielectric constant by acting as a nucleating agent and forming a nanostructure with large aspect ratio.

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.

Investigation on β-Polypropylene/Talc Composites

2012 ◽  
Vol 182-183 ◽  
pp. 259-264
Author(s):  
Jia Wei Duan ◽  
Qiang Dou
Keyword(s):  
Polarized Light ◽  
Nucleating Agent ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Melt Compounding ◽  
Β Phase ◽  
Α Phase ◽  
Melting And Crystallization

In this study polypropylene (PP) composites containing β-nucleating agent (NT-C) and talc filler were prepared by melt compounding. The melting and crystallization behavior, morphology and mechanical properties of the composites were studied by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), polarized light microscopy (PLM) and mechanical tests. The results indicate that talc suppresses the formation of β phase, but promotes the formation of α phase. The Izod notched impact strength and tensile strength of β-PP/talc composites are superior to those of PP/talc composites, indicating an outstanding balance of stiffness and toughness of β-PP/talc composites.

Crystalinity Properties of Carbon Nanotube-Polyvinylidene Fluoride Composites

2008 ◽  
Vol 1134 ◽  
Author(s):  
Xiaobing Shan ◽  
Pei-xuan Wu ◽  
Lin Zhang ◽  
Zhong-Yang Cheng
Keyword(s):  
Differential Scanning Calorimetry ◽  
Carbon Nanotube ◽  
Acid Treatment ◽  
Polyvinylidene Fluoride ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Β Phase ◽  
Solution Cast ◽  
Solution Cast Method

AbstractSingle-wall and multi-wall carbon nanotube blends (0 to 0.5 vol% ) with polyvinylidene fluoride (PVDF) have been prepared using solution cast method and characterized. By acid treatment, it has been observed that nanotube has been well functionalized and uniformly dispersed into the polymer. X-ray diffraction analysis coupled with differential scanning calorimetry (DSC) has revealed that carbon nanotube alters the crystallinity of PVDF and thereby enhances the β-phase in PVDF. Experimental results have demonstrated that enhancement of β-phase is a function of carbon nanotube concentration.

Blending and plasticising effects on the behaviour of poly(lactic acid)/poly(ε-caprolactone)

2018 ◽  
Vol 26 (5-6) ◽  
pp. 337-345 ◽  
Author(s):  
Nesrine Khitas ◽  
Kamira Aouachria ◽  
Mohamed Tahar Benaniba
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Triethyl Citrate ◽  
Acetyl Tributyl Citrate ◽  
The Degree Of Crystallinity

Polymer blending is one of the most convenient methods to be used to overcome the limitations of some single properties of polymers and to achieve the combinations required for specific applications. Another feasible common practice is the incorporation of additives of low molecular weight such as plasticisers to impart flexibility, improve toughness and lower the glass transition temperature ( Tg). This study focused on the effects of blending and plasticising on the crystallisation behaviour of poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL). PCL with longer degradation time compared with other polymers was blended with PLA to overcome the limitation of its brittleness and poor thermal stability. Acetyl tributyl citrate (ATBC) and acetyl triethyl citrate (TEC) were used as plasticiser in PLA/PCL blends. The rigid and plasticised blends at various ratios were analysed by differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. The results revealed a slight increase in the degree of crystallinity and a significant increase in the Tg of PLA due to the addition of PCL. The addition of ATBC has promoted a decrease in thermal stability of the blends. The slight increase in the degree of crystallinity suggested that PCL acted as a nucleating agent. The citrate plasticisers were shown to lower the Tg and have much more enhanced the crystallisation of PLA. Moreover, the rigid and plasticised blends were shown to be partially miscible.

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.

Preparation and characterization of poly(3-hydroxybutyrate)/ Cloisite25A nanocomposites

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Matko Erceg ◽  
Dražan Jozić
Keyword(s):  
Crystallization Rate ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Tg Analysis ◽  
Solution Intercalation ◽  
X Ray ◽  
Thermal Stability Of

Abstract Poly(3-hydroxybutyrate)/Cloisite25A (PHB/25A) nanocomposites were prepared by solution-intercalation method. The intercalation of PHB chains between the layers of Cloisite25A was observed by X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and non-isothermal thermogravimetry (TG) analysis were performed to study the thermal properties, crystallization and the thermal degradation of the prepared nanocomposites. DSC analysis indicates that Cloisite25A acts as a nucleating agent and increases the crystallization rate of PHB, but due to intercalation reduces its overall degree of crystallinity. TG analysis shows that addition of Cloisite25A enhances the thermal stability of PHB.

Degree of Crystallinity and β Phase Fraction of Polyvinylidene Fluoride Nanocomposites Containing Ionic Liquid and Graphene/Carbon Nanotube

2018 ◽  
Vol 39 (S2) ◽  
pp. E1208-E1215 ◽  
Author(s):  
Mohammad Hossein Ghajar ◽  
Mahmoud Mosavi Mashhadi ◽  
Mehrdad Irannejad ◽  
Seid Jebril ◽  
Mustafa Yavuz ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Carbon Nanotube ◽  
Polyvinylidene Fluoride ◽  
Phase Fraction ◽  
Degree Of Crystallinity ◽  
Β Phase

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.

scholarly journals Effect of Carbon Nanotube Loading on Electrical Properties of Electrospun Polyvinylidene Fluoride (PVDF) Fiber

2021 ◽  
Vol 2080 (1) ◽  
pp. 012015
Author(s):  
Jia Wei Lee ◽  
S.B Sharifah Shahnaz ◽  
A.Z Nur Hidayah ◽  
S. Yahud ◽  
Noorasikin Samat
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Peak Shift ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Β Phase ◽  
Graphite Sheets

Abstract Polyvinylidene fluoride (PVDF) is a high purity thermoplastic fluropolymer that use in the aircraft, electronics, and chemical industry. Carbon nanotube (CNTs) is made up of rolled up of graphite sheets, exhibits excellent chemical, thermal, mechanical properties, and large surface areas. PVDF fibers blended with CNTs were able to enhance the β-phase which contributes to piezoelectric properties. Electrospinning is the simplest and low-cost method to produce PVDF/CNT fibers by dissolving PVDF in solvent N, N-Dimethylformamide (DMF). 15wt% PVDF solution was used. CNT loading were varied at 0.0wt%, 0.35wt%, 0.80wt% and 1.00wt% with parameters of 20kV, tip-to-collector distance (TCD) 15cm and flow rate 1.0mLh-1. Scanning Electron Microscope (SEM), four-point probe and X-ray Diffraction (XRD) were used to determine the morphology and crystallinity of electrospun PVDF/CNT fibers. The SEM analysis concluded all fibers showed beaded structure due to low concentration of PVDF solution with insufficient ultrasonification and stirring, cause electrospraying and agglomeration. XRD and four-point probe analysis concluded PVDF/0.35wt%CNT showed the highest β-phase content with intense XRD peak and highest electrical conductivity. However, shift peak is observed among all fibres due to short electrospinning time leads to insufficient thickness of electrospun mat, which affects the mechanical properties of fibres and causes peak shift.

scholarly journals The Radial Piezoelectric Response from Three-Dimensional Electrospun PVDF Micro Wall Structure

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1368
Author(s):  
Guoxi Luo ◽  
Yunyun Luo ◽  
Qiankun Zhang ◽  
Shubei Wang ◽  
Lu Wang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Three Dimensional ◽  
Piezoelectric Response ◽  
Wall Structure ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Β Phase ◽  
Piezoelectric Energy ◽  
Novel Structure ◽  
Random Arrangement

The ability of electrospun polyvinylidene fluoride (PVDF) fibers to produce piezoelectricity has been demonstrated for a while. Widespread applications of electrospun PVDF as an energy conversion material, however, have not materialized due to the random arrangement of fibers fabricated by traditional electrospinning. In this work, a developed 3D electrospinning technique is utilized to fabricate a PVDF micro wall made up of densely stacked fibers in a fiber-by-fiber manner. Results from X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR) demonstrate that the crystalline structure of this PVDF wall is predominant in the β phase, revealing the advanced integration capability of structural fabrication and piezoelectric poling with this 3D electrospinning. The piezoelectric response along the radial direction of these PVDF fibers is measured while the toppled micro wall, comprised of 60 fibers, is sandwich assembled with a pair of top/bottom electrodes. The measured electrical output is ca. 0.48 V and 2.7 nA. Moreover, after constant mechanical compression happening over 10,000 times, no obvious reduction in the piezoelectric response has been observed. The combined merits of high-precision 3D fabrication, in situ piezoelectric poling, and high mechanical robust make this novel structure an attractive candidate for applications in piezoelectric energy harvesting and sensing.

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