scholarly journals Investigation of the dielectric properties of Sn – doped PMMA/PVA blends

2019 ◽  
Vol 12 (25) ◽  
pp. 105-112
Author(s):  
Ahamad A. Hasan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Frequency Range ◽  
Electrical Field ◽  
Weight Percentage ◽  
Casting Technique ◽  
Blend Ratios ◽  
The Relationship ◽  
Applied Electrical Field

Blends of Polymethyl methacrylate (PMMA)/polyvinyl alcohol (PVA) doped with 2% weight percentage of Sn were prepared with different blend ratios using casting technique. The measurements of A.C conductivity σa.c within the frequency range (25kHz – 5MHz) of undoped and Sn doped PMMA/PVA blends obeyed the relationship σ= Aws were the value of s within the range 0 > s > 1. The results showed that σa.c increases with the increase of frequency. The exponent s showed preceding increase with the increase of PVA content for PMMA/PVA blends doped with Sn. The dielectric constant, dielectric loss, A.C electrical conductivity are varied with the concentration of PVA in the blend and frequency of applied electrical field.

Simulation on Electrical Conductivity of CNTs/PE Composites

2014 ◽  
Vol 1035 ◽  
pp. 408-412
Author(s):  
Chang Ming Li ◽  
Chun Yang Li ◽  
Cheng Cheng Zhang ◽  
Ming Yue Fan ◽  
Yan Li Cheng ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Aspect Ratio ◽  
Simulation Models ◽  
Electrical Current ◽  
The Finite Element Method ◽  
Electrical Field ◽  
Electrical Field Strength ◽  
Orientation Degree ◽  
The Relationship ◽  
Applied Electrical Field

In order to investigate the electrical conductivity of carbon nanotubes (CNTs)/polyethylene (PE) composites, the relationship curves between the external electrical filed strength and the electrical conductivity of CNTs/PE composites with different microstructures were generated based on numerical simulation. The simulation models of CNTs/PE composites were designed through changing the content, aspect ratio and orientation degree of CNTs. After DC electrical field is applied between top and bottom surfaces of the composites, the distribution of electrical current density was calculated based on the finite element method by using the COMSOL simulating software, and then the electrical conductivity is obtained. Research results indicated the electrical conductivity of the composites increases significantly with the increase of aspect ratio of CNTs at the same CNT content and electrical field strength. As the orientation degree of CNTs along the applied electrical field increases, the electrical conductivity of the composites obviously increases. It can therefore be concluded that the changing of microstructures of CNTs/PE composites is effective to control the electrical conductivity of the composites.

scholarly journals Dielectrical and electrical properties of PVA-NaI composites

2019 ◽  
Vol 11 (22) ◽  
pp. 56-63
Author(s):  
Hussein Neama Najeeb
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Sodium Iodide ◽  
Electrical Field ◽  
Field Frequency ◽  
Casting Technique ◽  
Different Temperatures ◽  
Solution Casting Technique ◽  
Temperature Activation ◽  
Applied Electrical Field

                The electrical characteristics of polyvinyl alcohol PVA doped with different concentrations (0, 1, 2, 3 and 4wt%) of sodium  iodide NaI powder were studied. The films are prepared using solution casting technique, in order to investigate the effect of sodium iodide NaI additions on the electrical properties of PVA host. The D.C conductivity measured by measuring the D.C electrical resistance using the Keithly Electrometer type 616C, and for different temperatures ranging from 30 – 70oC.           The dielectric properties measured by measuring the capacitor and the loss angle tangent as a function of the alternating electric field frequency using the Agilent impedance analyzer 4294A, within the frequency range 50 – 6 ×106 Hz at room temperature.  The experimental results showed that the dielectric constant is decrease with increase frequency of applied electrical field and increase with increasing concentrations, dielectric loss is increase with increasing frequency of applied electrical field to be 1MHz after this it was decreasing, A.C electrical conductivity are increasing with increasing frequency of applied electrical field, also, the results showed that the D.C electrical conductivity are increasing with increase concentration of NaI and temperature, activation energy are decreasing with increase concentration of additive salt.     

scholarly journals Determination of Relationship between Dielectric Properties, Compressive Strength, and Age of Concrete with Rice Husk Ash Using Planar Coaxial Probe

2016 ◽  
Vol 16 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Nawarat Piladaeng ◽  
Niwat Angkawisittpan ◽  
Sahalaph Homwuttiwong
Keyword(s):  
Dielectric Constant ◽  
Compressive Strength ◽  
Dielectric Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Planar Structure ◽  
Frequency Range ◽  
The Relationship ◽  
Coaxial Probe

Abstract This paper deals with an investigation of the dielectric properties of concretes that includes rice husk ash using a planar coaxial probe. The planar coaxial probe has a planar structure with a microstrip and coaxial features. The measurement was performed over the frequency range of 0.5-3.5 GHz, and concrete specimens with different percentages of rice husk ash were tested. The results indicated that the dielectric constant of the concretes was inversely proportional to the frequency, while the conductivity was proportional to the frequency. The dielectric constant decreased with the increasing age of the concrete at the frequency of 1 GHz. The conductivity of the concrete decreased with the increasing age of the concrete at the frequency of 3.2 GHz. In addition, the dielectric constant and the conductivity decreased when the compressive strength increased. It was also shown that the obtained dielectric properties of the concrete could be used to investigate the relationship between the compressive strength and age of the concrete. Moreover, there is an opportunity to apply the proposed probe to determine the dielectric properties of other materials.

scholarly journals Preparation and studying Structural and Electrical properties of nano Co3O4

2019 ◽  
Vol 24 (6) ◽  
pp. 126
Author(s):  
Nawar Thamer Mohammed ◽  
Wasfi Mohammed Kadem
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Sol Gel ◽  
Frequency Range ◽  
Nano Powder ◽  
Structural And Electrical Properties ◽  
Electrical And Dielectric Properties ◽  
Lcr Meter

In this study (Cobalt oxide) nano powder prepared using sol-gel method with a crystallite size 22 nm By testing XRD  and by matching with card (JCPDS) files No.( 00-042-1467). Electrical and dielectric properties like (Dielectric constant, resistivity, electrical conductivity) are studied by LCR meter with frequency range from (50 Hz) to (5 MHz ). It was noted that the resistivity and dielectric constant was decreasing while electrical conductivity increased with increased  frequency    http://dx.doi.org/10.25130/tjps.24.2019.118  

scholarly journals Electrical Conductivity and Dielectric Properties of Bulk Glass V2O5 (ZnO, PbO) SrO FeO

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
M. S. Aziz ◽  
A. G. Mostafa ◽  
A. M. Youssef ◽  
S. M. S. Youssif
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Dielectric Dispersion ◽  
Bulk Glass ◽  
Frequency Range ◽  
Glassy System ◽  
Dielectric Parameters

The AC conductivity and dielectric parameters of the glassy system of (70-x) V2O5· x(Zn/Pb)· 10SrO · 20FeO (x = 0, 5, 10, and 15) glasses have been investigated. The frequency and temperature dependence of dielectric constant (ε′) and dielectric loss (ε′′) is studied in the frequency range 100 Hz–5 MHz and in the temperature range 300–460 K. Dielectric dispersion is observed in all samples as Zn/Pb increase content in the (70-x)V2O5· x(Zn/Pb)·10SrO·20FeO systems. These results are explained on the basis of a Debye-type relaxation. It is also observed that the activation energy increases on increasing the Zn/Pb contents in this system.

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

2021 ◽  
pp. 096739112110147
Author(s):  
Ufuk Abaci ◽  
H Yuksel Guney ◽  
Mesut Yilmazoglu
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Dielectric Properties ◽  
Methyl Methacrylate ◽  
Pure Pmma ◽  
Segmental Mobility ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Casting Technique ◽  
Lcr Meter

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

scholarly journals Dielectric properties of the system: 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4᾽-methylaniline

2021 ◽  
Vol 16 (2) ◽  
pp. 138-147
Author(s):  
S. A. Syrbu ◽  
M. S. Fedorov ◽  
E. A. Lapykina ◽  
V. V. Novikov
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Anisotropy ◽  
Specific Electrical Conductivity ◽  
Conductivity Anisotropy ◽  
Independent Molecules ◽  
System Properties ◽  
The Individual

Objectives. Our aim was to study the dielectric properties of the 4-n-pentyloxybenzoic acid– N-(4-n-butyloxybenzylidene)-4’-methylaniline system and reveal how different concentrations of N-(4-n-butyloxybenzylidene)-4’-methylaniline additives affect the dielectric properties of 4-n-pentyloxybenzoic acid.Methods. System properties were investigated using polarization thermomicroscopy and dielcometry.Results. We found that dielectric anisotropy changes its sign from positive to negative at the transition temperature of the high-temperature nematic subphase to the low-temperature one. The anisotropy of the dielectric constant of N-4-n-butoxybenzylidene-4’-methylaniline has a positive value and increases as to the system approaches the crystalline phase. The crystal structure of the 4-n-pentyloxybenzoic acid contains dimers formed by two independent molecules due to a pair of hydrogen bonds. The crystal structure of N-(4-n-butoxybenzylidene)-4’-methylaniline contains associates formed by orientational interactions of two independent molecules. 4-n-Pentyloxybenzoic acid dimers (270 nm) and associates of N-4-n-butoxybenzylidene-4’- methylaniline (250 nm) proved to have approximately the identical length. Considering the close length values of the structural units of both compounds and the dielectric anisotropy sign, we assume that the N-4-n-butoxybenzylidene-4’-methylaniline associates are incorporated into the supramolecular structure of the 4-n-pentyloxybenzoic acid. The specific electrical conductivity of the compounds under study lies between 10−7 and 10−12 S∙cm−1. The relationship between the specific electrical conductivity anisotropy and the system composition in the nematic phase at the identical reduced temperature, obtained between 100 and 1000 Hz is symbatic. However, the electrical conductivity anisotropy values of the system obtained at 1000 Hz are lower compared to those obtained at 100 Hz. At N-(4-n-butoxybenzylidene)-4’-methylaniline concentrations between 30 and 60 mol %, the electrical conductivity anisotropy values are higher than those of the individual component.Conclusions. A change in the sign of the dielectric constant anisotropy of the 4-n-pentyloxybenzoic acid during nematic subphase transitions was established. We showed that the system has the highest dielectric constant anisotropy value when components have an equal number of moles. Highest electrical conductivity anisotropy values are observed when the concentration of the N-4-n-butoxybenzylidene-4᾽-methylaniline system lies between 30 and 60 mol %. 

scholarly journals A.C conductivity and dielectric properties of (PVA/ PEO) blends doped with MWCNTs

2019 ◽  
Vol 14 (30) ◽  
pp. 64-72
Author(s):  
Ahmad A. Hasan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
The Other ◽  
Poly Vinyl Alcohol ◽  
Conductivity Measurements ◽  
Frequency Range ◽  
Maximum Value ◽  
Multi Walled Carbon Nanotube ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

A.C electrical conductivity and dielectric properties for poly(vinyl alcohol) (PVA) /poly (ethylene oxide) (PEO) blends undopedand doped with multi-walled carbon nanotube (MWCNTs) withdifferent concentrations (1, and 3 wt %) in the frequency range(25x103 - 5x106 Hz) were investigated. Samples of (PVA/PEO)blends undoped and doped with MWCNTs were prepared usingcasting technique. The electrical conductivity measurements showedthat σA.C is frequency dependent and obey the relation σA.C =Aωs forundoped and doped blends with 1% MWCNTs, while it is frequencyindependent with increases of MWCNTs content to 3%. Theexponent s showed proceeding increase with the increase of PEOratio (≥50%) for undoped blends samples, while s value for dopedblends exhibits to change in different manner, i.e. s increases andreach maximum value at 50/50 PVA/PEO, then decreases forresidual doped blends samples with 1% MWCNTs on the other handthe exponent s decrease and reach minimum value at 50/50PVA/PEO for samples doped with 3% MWCNTs, then return toincrease. The results explained in different terms.

Effect of moisture content on dielectric properties of banana leaves and peels in frequency range of 1–20 GHz

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Soumya Sundar Pattanayak ◽  
Soumen Biswas
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Measurement Data ◽  
Banana Peel ◽  
Frequency Range ◽  
Proposed Model ◽  
Banana Leaves ◽  
Banana Leaf

Abstract The quality of agricultural products can be remotely sensed and enhanced by determining the dielectric properties. This paper studies the dielectric properties of banana leaf and banana peel over the frequency range 1–20 GHz using the open-ended coaxial probe (OCP) method. A new curve fitting model is proposed to characterize the dielectric properties of banana leaf and banana peel. The different moisture content (MC) levels are considered for both banana leaf and banana peel samples and, their dielectric properties are characterized. Further, the banana leaf and banana peel’s measurement data are compared with the data obtained using the proposed model. In addition, Root Mean Square Error (RMSE) and R-squared (R 2) are calculated to validate the performance of the proposed model. In case of banana leaf at 68.26% MC, the dielectric constant achieves the value of R 2 and RMSE of 0.98 and 0.0648, respectively. Similarly, dielectric loss achieves the value of R 2 and RMSE of 0.88 and 0.0795, respectively. Further, for banana peel at 80.89% MC, the dielectric constant achieves the value of R 2 and RMSE of 0.99 and 0.2989, respectively. Similarly, dielectric loss achieves the value of R 2 and RMSE of 0.96 and 0.6132, respectively.

Effect of Sintering Temperature on Dielectric Properties of CaCu3Ti4O12 Ceramics Prepared by Mechanochemical Process

2014 ◽  
Vol 974 ◽  
pp. 157-161
Author(s):  
Masturah Mohamed ◽  
Mahesh Talari ◽  
Mohd Salleh Mohd Deni ◽  
Azlan Zakaria
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Processing Conditions ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Grain Sizes ◽  
Barrier Capacitance ◽  
Different Temperatures ◽  
Increasing Temperature

CaCu3Ti4O12(CCTO) is well known to have colossal dielectric constant in the range of 105.It is widely accepted that this phenomenon may be attributed to internal layer barrier capacitance (IBLC) model. The dielectric properties of CCTO were reported to be strongly dependent on the processing conditions and grain size. In this work, CCTO samples with different grain sizes were produced by varying sintering temperature in order to investigate IBLC effect on dielectric properties of CCTO. The samples were sintered at four different temperatures, (T=1100°C, 1050°C, 1000°C and 950°C). Dielectric measurements were carried out for the samples in the frequency range of 102– 106Hz using impedance spectrometer. Electron micrographs showed that increasing temperature promoted the grain growth of CCTO while sintering. The internal crystalline defects are seen to play major role by increasing the grain conductivity in dipole formation and increased the dielectric constant of the samples.

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