scholarly journals Changes in Permittivity of the Piezoelectric Material PVDF as Functions of the Electrical Field and Temperature

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5736
Author(s):  
You Zhou ◽  
Mona Zaghloul

Polyvinylidene Fluoride (PVDF) is becoming a widely used piezoelectric material because of its flexibility, low cost, light weight, and biocompatibility. Its electronic properties, such as its permittivity, can be affected by material crystal structure variations, which also greatly impact the material’s application. It is known that external stress and electrical fields can alter the crystal structure of piezoelectric material. In this research, we aim to investigate the relationship between the external electrical field and the permittivity property of PVDF material. The basic standard equations, finite element analysis, and experimental measurement are included in this paper. By using sweeping voltages from −25 V to +25 V using an Agilent Technologies B1500A Semiconductor Device Analyzer, an increase in the permittivity of the PVDF material is observed. In this work, the study of the permittivity change under the application of different electrical fields at room temperature is presented, and the application of the electrical field under different temperatures is also studied and presented.

1993 ◽  
Vol 27 (10) ◽  
pp. 95-99 ◽  
Author(s):  
G. S. Solt

Depth filtration of liquids is a well established process. Its main drawback is that it does not effectively remove particles smaller than about 2-3 µm diameter, because they do not normally approach near enough to the surface of the medium to become attached to it. A static electrical field overcomes this by promoting electrophoretic movement of the particles. The work has studied particle removal from low conductivity water through fibrous depth filters and has covered a variety of fibres with different physical properties. The results yield a fibre efficiency series, which suggest the relationship between filtration efficiency and the electrical properties of the fibre.


10.6036/9812 ◽  
2021 ◽  
Vol 96 (4) ◽  
pp. 364-367
Author(s):  
FEDERICO LEON ZERPA ◽  
ALEJANDRO RAMOS PÉREZ

This article presents a low-cost experimental design proposal to understand and learn the relationship between the electrical conductivity CE of brackish water and its temperature T, in which an embedded system (Arduino Nano). This design has been made to be used as good practices in subjects of the University Degrees with competences in the area of production and water treatment, both for civil and industrial consumption, mainly in the School of Engineering. Industrial and Civil of the University of Las Palmas de Gran Canaria. Furthermore, this design is mainly characterized by its versatility, when considering different situations, and using free tools and open source; both regarding computer applications, as in the components and elements used. This last aspect turns out to be an important characteristic, as it will allow the design to be modified, economically, according to future needs, by the students or by the teachers. A series of tests have been implemented with different types of common salts in brackish waters, at different temperatures. Results obtained from the design are shown, following suitable methods to observe the variability of the electrical conductivity of the solutions with the temperature, and with the type of salt used. These experimental results demonstrate that the experimental design can be used to understand and learn the proposed objective, as well as to obtain the relationship between CE and T, in the form of a straight line fit. Keywords: Electrical conductivity, reverse osmosis, water quality


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1337-1345
Author(s):  
Chuan Zhao ◽  
Feng Sun ◽  
Junjie Jin ◽  
Mingwei Bo ◽  
Fangchao Xu ◽  
...  

This paper proposes a computation method using the equivalent magnetic circuit to analyze the driving force for the non-contact permanent magnet linear drive system. In this device, the magnetic driving force is related to the rotation angle of driving wheels. The relationship is verified by finite element analysis and measuring experiments. The result of finite element simulation is in good agreement with the model established by the equivalent magnetic circuit. Then experiments of displacement control are carried out to test the dynamic characteristic of this system. The controller of the system adopts the combination control of displacement and angle. The results indicate that the system has good performance in steady-state error and response speed, while the maximum overshoot needs to be reduced.


Author(s):  
Yasunori Goto ◽  
Hiroomi Eguchi ◽  
Masaru Iida

Abstract In the automotive IC using thick-film silicon on insulator (SOI) semiconductor device, if the gettering capability of a SOI wafer is inadequate, electrical characteristics degradation by metal contamination arises and the yield falls. At this time, an automotive IC was made experimentally for evaluation of the gettering capability as one of the purposes. In this IC, one of the output characteristics varied from the standard, therefore failure analysis was performed, which found trace metal elements as one of the causes. By making full use of 3D perspective, it is possible to fabricate a site-specific sample into 0.1 micrometre in thickness without missing a failure point that has very minute quantities of contaminant in a semiconductor device. Using energy dispersive X-ray, it is possible to detect trace metal contamination at levels 1E12 atoms per sq cm. that are conventionally detected only by trace element analysis.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


2021 ◽  
Author(s):  
Xiaojing Zhang ◽  
xinyi Ge ◽  
Zhigang Shen ◽  
Han Ma ◽  
Jingshi Wang ◽  
...  

Compared with environmentally harmful binder polyvinylidene fluoride (PVDF) in Li-ion batteries (LIBs), water-based binders have many advantages, such as low cost, rich sources and environmental friendliness. In this study, various...


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Stelbin Peter Figerez ◽  
Sudeshna Patra ◽  
G Rajalakshmi ◽  
Tharangattu N Narayanan

Abstract Respiratory masks having similar standards of ‘N95’, defined by the US National Institute for Occupational Safety and Health, will be highly sought after, post the current COVID-19 pandemic. Here, such a low-cost (∼$1/mask) mask design having electrostatic rechargeability and filtration efficiency of >95% with a quality factor of ∼20 kPa−1 is demonstrated. This filtration efficacy is for particles of size 300 nm. The tri-layer mask, named PPDFGO tri, contains nylon, modified polypropylene (PPY), and cotton nonwoven fabrics as three layers. The melt-spun PPY, available in a conventional N95 mask, modified with graphene oxide and polyvinylidene fluoride mixture containing paste using a simple solution casting method acts as active filtration layer. The efficacy of this tri-layer system toward triboelectric rechargeability using small mechanical agitations is demonstrated here. These triboelectric nanogenerator (TENG)-assisted membranes have high electrostatic charge retention capacity (∼1 nC/cm2 after 5 days in ambient condition) and high rechargeability even in very humid conditions (>80% RH). A simple but robust permeability measurement set up is also constructed to test these TENG-based membranes, where a flow rate of 30–35 L/min is maintained during the testing. Such a simple modification to the existing mask designs enabling their rechargeability via external mechanical disturbances, with enhanced usability for single use as well as for reuse with decontantamination, will be highly beneficial in the realm of indispensable personal protective equipment.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 913
Author(s):  
Jinyi Wang ◽  
Sen Yang

The development of low-cost and high-efficiency catalysts for wastewater treatment is of great significance. Herein, nanoporous Cu/Cu2O catalysts were synthesized from MnCu, MnCuNi, and MnCuAl with similar ligament size through one-step dealloying. Meanwhile, the comparisons of three catalysts in performing methyl orange degradation were investigated. One of the catalysts possessed a degradation efficiency as high as 7.67 mg·g−1·min−1. With good linear fitting by the pseudo-first-order model, the reaction rate constant was evaluated. In order to better understand the degradation process, the adsorption behavior was considered, and it was divided into three stages based on the intra-particle diffusion model. Three different temperatures were applied to explore the activation energy of the degradation. As a photocatalytic agent, the nanoporous structure of Cu/Cu2O possessed a large surface area and it also had low activation energy, which were beneficial to the excellent degradation performance.


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