scholarly journals Piezoelastic PVDF/TPU Nanofibrous Composite Membrane: Fabrication and Characterization

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1634 ◽  
Author(s):  
Eman Elnabawy ◽  
Ahmed H. Hassanain ◽  
Nader Shehata ◽  
Anton Popelka ◽  
Remya Nair ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Vinylidene Fluoride ◽  
Thermoplastic Polyurethane ◽  
Weight Ratio ◽  
Composite Membranes ◽  
Piezoelectric Response ◽  
Wearable Electronics ◽  
Electric Voltage ◽  
The Impact ◽  
Piezoelectric Characteristics

Poly (vinylidene fluoride) nanofibers (PVDF NFs) have been extensively used in energy harvesting applications due to their promising piezoresponse characteristics. However, the mechanical properties of the generated fibers are still lacking. Therefore, we are presenting in this work a promising improvement in the elasticity properties of PVDF nanofibrous membrane through thermoplastic polyurethane (TPU) additives. Morphological, physical, and mechanical analyses were performed for membranes developed from different blend ratios. Then, the impact of added weight ratio of TPU on the piezoelectric response of the formed nanofibrous composite membranes was studied. The piezoelectric characteristics were studied through impulse loading testing where the electric voltage had been detected under applied mass weights. Piezoelectric characteristics were investigated further through a pressure mode test the developed nanofibrous composite membranes were found to be mechanically deformed under applied electric potential. This work introduces promising high elastic piezoelectric materials that can be used in a wide variety of applications including energy harvesting, wearable electronics, self-cleaning filters, and motion/vibration sensors.

A large piezoelectric response in highly-aligned electrospun poly(vinylidene fluoride/trifluoroethylene) nanofiber webs for wearable energy harvesting

2020 ◽  
Vol 32 (1) ◽  
pp. 015401 ◽  
Author(s):  
Mohammad A Barique ◽  
Yoichiro Neo ◽  
Masaji Noyori ◽  
Lia Aprila ◽  
Masaya Asai ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Vinylidene Fluoride ◽  
Piezoelectric Response ◽  
Poly Vinylidene Fluoride

Preparation and Characterization of Konjac/Gelatin Composite Nanofibrous Membranes

2013 ◽  
Vol 562-565 ◽  
pp. 887-890 ◽  
Author(s):  
Xin Chen Du ◽  
Xiao Yan Lin ◽  
Yuan Hao Huang ◽  
Ying Li ◽  
Xue Gang Luo
Keyword(s):  
Feeding Rate ◽  
Fiber Diameter ◽  
Weight Ratio ◽  
Composite Membranes ◽  
Electrospinning Process ◽  
Average Fiber Diameter ◽  
Electric Voltage ◽  
Technical Parameters ◽  
Nanofibrous Membranes

A composite membrane of konjac/gelatin was prepared by electrospinning process. Gelatin and konjac were dissolved in acetic acid with different concentration and the resulting blend sol was electrospun into the composite nanofibrous membranes. The influence of technical parameters on morphology and diameter of nanofibers was investigated by Scanning Electron Microscope (SEM). The results show that the concentration of gelatin/konjac blend sol affects significantly on the fiber diameter and the morphology of composite membranes, and the increase of the voltage results in the decrease of the fiber diameter. The composite nanofibrous membranes with the average fiber diameter ranging from 356nm to 463nm were fabricated by electrospinning at the following conditions: 25% (w/v) of the concentration of gelatin/konjac blend sol (weight ratio of gelatin to konjac=125/1), 20KV of electric voltage, 0.0025mm s-1 of the feeding rate, 42°C of the electrospinning temperature and 15cm of receiving distance.

scholarly journals Novel Flexible PVDF-TrFE and PVDF-TrFE/ZnO Pressure Sensor: Fabrication, Characterization and Investigation

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 602
Author(s):  
Mingran Liu ◽  
Yang Liu ◽  
Limin Zhou
Keyword(s):  
Pressure Sensor ◽  
Vinylidene Fluoride ◽  
Pressure Sensors ◽  
Weight Ratio ◽  
Composite Membranes ◽  
Annealing Process ◽  
Voltage Response ◽  
Electrical Signals ◽  
Β Phase ◽  
Phase Crystal

With the development of human healthcare devices, smart sensors, e-skins, and pressure sensors with outstanding sensitivity, flexibility, durability and biocompatibility have attracted more and more attention. In this paper, to develop a novel flexible pressure sensor with high sensitivity, different poly (vinylidene fluoride-trifluoroethylene) (PVDF-TrFE)-based composite membranes were fabricated, characterized and tested. To improve the β-phase crystallinity and piezoelectricity of the membranes, and for the purpose of comparison, nano ZnO particles with different concentrations (99:1, 9:1 in a weight ratio of PVDF-TrFE to ZnO) were, respectively added into PVDF-TrFE polymer acting as a nucleating agent and dielectric material. To facilitate the formation of β-phase crystal, the membranes were fabricated by electrospinning method. After the electrospinning, an annealing process was conducted to the fabricated membranes to increase the size and content of β-phase crystal. Then, the fabricated PVDF-TrFE membranes, acting as the core sensing layer, were, respectively built into multiple prototype sensors in a sandwich structure. The sensitivity of the prototype sensors was tested by an auto-clicker. The stimulation of the auto-clicker on the prototype sensors generated electrical signals, and the electrical signals were collected by a self-built testing platform powered by LabVIEW. As a result, combining the addition of ZnO nanofillers and the annealing process, a highly sensitive pressure sensor was fabricated. The optimal peak-to-peak voltage response generated from the prototype sensor was 1.788 V which shows a 75% increase compared to that of the pristine PVDF-TrFE sensor. Furthermore, a human pulse waveform was captured by a prototype sensor which exhibits tremendous prospects for application in healthcare devices.

Preparation and Characterization of KGM/PVA Composite Nanofibrous Membranes

2013 ◽  
Vol 734-737 ◽  
pp. 2145-2150
Author(s):  
Xin Chen Du ◽  
Xiao Yan Lin ◽  
Yuan Hao Huang ◽  
Ying Li ◽  
Xue Gang Luo
Keyword(s):  
Feeding Rate ◽  
Fiber Diameter ◽  
Weight Ratio ◽  
Composite Membranes ◽  
Electrospinning Process ◽  
Average Fiber Diameter ◽  
Electric Voltage ◽  
Technical Parameters ◽  
Nanofibrous Membranes

A composite membrane of KGM/PVA was prepared by electrospinning process. KGM and PVA were dissolved in water and acetic acid (volum:6/4) with different concentration and the resulting blend sol was electrospun into the composite nanofibrous membranes. The influence of technical parameters on morphology and diameter of nanofibers was investigated by Scanning Electron Microscope (SEM). The results show that the concentration of KGM/PVA blend sol affects significantly on the fiber diameter and the morphology of composite membranes, and the increase of the voltage results in the decrease of the fiber diameter. The composite nanofibrous membranes with the average fiber diameter ranging from 87.5nm to 165.6nm were fabricated by electrospinning at the following conditions: 10% (w/v) of the concentration of KGM/PVA blend sol (weight ratio of KGM to PVA=4/6), 25KV of electric voltage, 0.0025mm s-1 of the feeding rate, 45°C of the electrospinning temperature and 16cm of receiving distance.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

scholarly journals Composite Ferroelectric Membranes Based on Vinylidene Fluoride-Tetrafluoroethylene Copolymer and Polyvinylpyrrolidone for Wound Healing

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Tamara S. Tverdokhlebova ◽  
Ludmila S. Antipina ◽  
Valeriya L. Kudryavtseva ◽  
Ksenia S. Stankevich ◽  
Ilya M. Kolesnik ◽  
...  
Keyword(s):  
Wound Healing ◽  
Vinylidene Fluoride ◽  
Ferroelectric Properties ◽  
Composite Membranes ◽  
Modern Medicine ◽  
In Vivo Studies ◽  
Cytotoxic Effects ◽  
Complex Process ◽  
Purulent Wounds

Wound healing is a complex process and an ongoing challenge for modern medicine. Herein, we present the results of study of structure and properties of ferroelectric composite polymer membranes for wound healing. Membranes were fabricated by electrospinning from a solution of vinylidene fluoride/tetrafluoroethylene copolymer (VDF–TeFE) and polyvinylpyrrolidone (PVP) in dimethylformamide (DMF). The effects of the PVP content on the viscosity and conductivity of the spinning solution, DMF concentration, chemical composition, crystal structure, and conformation of VDF–TeFE macromolecules in the fabricated materials were studied. It was found that as PVP amount increased, the viscosity and conductivity of the spinning solutions decreased, resulting in thinner fibers. Using FTIR and XRD methods, it was shown that if the PVP content was lower than 50 wt %, the VDF–TeFE copolymer adopted a flat zigzag conformation (TTT conformation) and crystalline phases with ferroelectric properties were formed. Gas chromatography results indicated that an increase in the PVP concentration led to a higher residual amount of DMF in the material, causing cytotoxic effects on 3T3L1 fibroblasts. In vivo studies demonstrated that compared to classical gauze dressings impregnated with a solution of an antibacterial agent, ferroelectric composite membranes with 15 wt % PVP provided better conditions for the healing of purulent wounds.

scholarly journals Retraction: A bio-based piezoelectric nanogenerator for mechanical energy harvesting using nanohybrid of poly(vinylidene fluoride)

2021 ◽  
Author(s):  
Anna Rulka
Keyword(s):  
Energy Harvesting ◽  
Vinylidene Fluoride ◽  
Mechanical Energy ◽  
Poly Vinylidene Fluoride

Retraction for ‘A bio-based piezoelectric nanogenerator for mechanical energy harvesting using nanohybrid of poly(vinylidene fluoride)’ by Pralay Maiti et al., Nanoscale Adv., 2019, 1, 3200–3211, DOI: 10.1039/C9NA00214F.

scholarly journals Studies on the electrostatic effects of stretched PVDF films and nanofibers

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yixuan Lin ◽  
Yuqiong Zhang ◽  
Fan Zhang ◽  
Meining Zhang ◽  
Dalong Li ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Polarized Light ◽  
Transition Process ◽  
Open Circuit ◽  
Wearable Electronics ◽  
Energy Harvesters ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Piezoelectric Effects ◽  
Energy Harvesting Devices

AbstractThe electroactive β-phase in Poly (vinylidene fluoride, PVDF) is the most desirable conformation due to its highest pyro- and piezoelectric properties, which make it feasible to be used as flexible sensors, wearable electronics, and energy harvesters etc. In this study, we successfully developed a method to obtain high-content β-phase PVDF films and nanofiber meshes by mechanical stretching and electric spinning. The phase transition process and pyro- and piezoelectric effects of stretched films and nanofiber meshes were characterized by monitoring the polarized light microscopy (PLM) images, outputting currents and open-circuit voltages respectively, which were proved to be closely related to stretching ratio (λ) and concentrations. This study could expand a new route for the easy fabrication and wide application of PVDF films or fibers in wearable electronics, sensors, and energy harvesting devices.

scholarly journals Particle Size Effect of Lanthanum-Modified Bismuth Titanate Ceramics on Ferroelectric Effect for Energy Harvesting

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sangmo Kim ◽  
Thi My Huyen Nguyen ◽  
Rui He ◽  
Chung Wung Bark
Keyword(s):  
Particle Size ◽  
Energy Harvesting ◽  
High Speed ◽  
High Performance ◽  
Bismuth Titanate ◽  
Vinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Renewable Energy Sources ◽  
Particle Size Effect ◽  
Ferroelectric Materials

AbstractPiezoelectric nanogenerators (PNGs) have been studied as renewable energy sources. PNGs consisting of organic piezoelectric materials such as poly(vinylidene fluoride) (PVDF) containing oxide complex powder have attracted much attention for their stretchable and high-performance energy conversion. In this study, we prepared a PNG combined with PVDF and lanthanum-modified bismuth titanate (Bi4−XLaXTi3O12, BLT) ceramics as representative ferroelectric materials. The inserted BLT powder was treated by high-speed ball milling and its particle size reduced to the nanoscale. We also investigated the effect of particle size on the energy-harvesting performance of PNG without polling. As a result, nano-sized powder has a much larger surface area than micro-sized powder and is uniformly distributed inside the PNG. Moreover, nano-sized powder-mixed PNG generated higher power energy (> 4 times) than the PNG inserted micro-sized powder.

scholarly journals Ultrahigh Ballistic Resistance of Twisted Bilayer Graphene

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 206
Author(s):  
Qing Peng ◽  
Sheng Peng ◽  
Qiang Cao
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Bilayer Graphene ◽  
Energy Propagation ◽  
Dynamic Simulations ◽  
Protective Material ◽  
Impact Performance ◽  
Ballistic Resistance ◽  
Twisted Bilayer Graphene ◽  
The Impact

Graphene is a good candidate for protective material owing to its extremely high stiffness and high strength-to-weight ratio. However, the impact performance of twisted bilayer graphene is still obscure. Herein we have investigated the ballistic resistance capacity of twisted bilayer graphene compared to that of AA-stacked bilayer graphene using molecular dynamic simulations. The energy propagation processes are identical, while the ballistic resistance capacity of the twisted bilayer graphene is almost two times larger than the AA-bilayer graphene. The enhanced capacity of the twisted bilayer graphene is assumed to be caused by the mismatch between the two sheets of graphene, which results in earlier fracture of the first graphene layer and reduces the possibility of penetration.

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