NanoDielectric Theories

2021 ◽  
pp. 95-141
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Polymer Matrix ◽  
Power Law ◽  
Theoretical Models ◽  
Nanocomposite Materials ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Polymer Filler ◽  
Exponential Power

This chapter sheds light on the recent nanotechnology theoretical models for interphase power law IPL model, inhomogeneous interphase, and multi-nanoparticles technique. Moreover, this chapter reviews deliberate hypothetical researches of the effective dielectric constant for polymer/filler nanocomposites and its reliance on “filler concentration, the interphase interactions, polymer filler dielectric constant, and interphase dielectric constant.” This chapter also investigates the prediction of the dielectric constant of new nanocomposite materials dependent upon exponential power law model. Thus, this work moves from the dielectric properties of beginning polymer matrix forward and predicts the dielectric properties of new nanocomposite materials to be utilized for high voltage and directing materials by adding specified nanoparticles with polymer matrix.

scholarly journals Characterization of percolation behavior in conductor–dielectric 0-3 composites

2014 ◽  
Vol 04 (04) ◽  
pp. 1450035 ◽  
Author(s):  
Lin Zhang ◽  
Patrick Bass ◽  
Zhi-Min Dang ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Percolation Threshold ◽  
Frequency Dependence ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Percolation Behavior ◽  
The Matrix ◽  
The Relationship

The equation ε eff ∝ (ϕc - ϕ)-s which shows the relationship between effective dielectric constant (εeff) and the filler concentration (φ), is widely used to determine the percolation behavior and obtain parameters, such as percolation threshold φc and the power constant s in conductor–dielectric composites (CDCs). Six different systems of CDCs were used to check the expression by fitting experimental results. It is found that the equation can fit the experimental results at any frequency. However, it is found that the fitting constants do not reflect the real percolation behavior of the composites. It is found that the dielectric constant is strongly dependent on the frequency, which is mainly due to the fact that the frequency dependence of the dielectric constant for the composites close to φc is almost independent of the matrix.

scholarly journals Core–shell structured Ag@C nanocables for flexible ferroelectric polymer nanodielectric materials with low percolation threshold and excellent dielectric properties

RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Zhihui Chen ◽  
Hengfeng Li ◽  
Guangyou Xie ◽  
Ke Yang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Percolation Threshold ◽  
Nanocomposite Materials ◽  
Core Shell ◽  
Ferroelectric Polymer

Flexible Ag@C-NC/PVDF nanocomposite materials with low percolation threshold and dielectric constant of 295 at 1 kHz.

The Effect of Octa(Maleimidophenyl)Silsesquioxane on Thermal and Dielectric Properties of Bismaleimide-Triazine Resins

2008 ◽  
Vol 47-50 ◽  
pp. 1161-1164
Author(s):  
Ding Sheng Yu ◽  
Hong Wei Cao ◽  
Ri Wei Xu
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Dielectric Properties ◽  
Bisphenol A ◽  
Hybrid Materials ◽  
Polymer Matrix ◽  
Diglycidyl Ether ◽  
Cyanate Ester ◽  
Onset Temperature ◽  
Ft Ir

BT resins composed of 4,4’-bismaleimidodiphenylmethane (BMI) and 2,2’-bis-(4-cyanatophenyl)propane (BCE) were modified by octa(maleimidophenyl) silsesquioxane (OMPS). It was found that the curing reaction of BCE were accelerated by OMPS, and the onset temperature of the cyclotrimerization was reduced up to 95.5°C (by DSC). As demonstrated by DSC and FT-IR, there was no evidence indicated the co-reaction between maleimide and cyanate ester. 2,2’-diallyl bisphenol A (DBA) and diglycidyl ether of bisphenol A (E-51) were also used to enhance the toughness of BT resins, and the formulated BTA and BTE resins were obtained. The results of DMA and TG show that the BT, BTA, and BTE resins containing 1wt% of OMPS exhibit enhanced thermal properties in comparison with pristine BT0, BTA0, and BTE0 resins, while more content of OMPS may impair the polymer matrix, though the effect of OMPS was slight. The dielectric constant of these hybrid materials were reduced by incorporation of OMPS, while overmuch contents of OMPS were disadvantageous for dielectric constant due to the aggregation of OMPS.

scholarly journals ENHANCING THE PERMITTIVITY, PERMEABILITY AND MORPHOLOGY OF ZNO-PCL NANOCOMPOSITES VIA NANO INCLUSION TREATMENT

2019 ◽  
pp. 1-7
Author(s):  
Abubakar Yakubu ◽  
Zulkifly Abba ◽  
Suleiman Sahabi
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Elemental Composition ◽  
Microwave Absorption ◽  
Polymer Matrix ◽  
Strong Interaction ◽  
Absorption Peak ◽  
Nano Particles ◽  
Melt Blending ◽  
High Dielectric

This study involves an investigation to ascertain the effect of ZnO nano inclusion on the evolution and dielectric properties of ZnO-PCL nanocomposites. The effect of the nano inclusion towards attenuation of the composites is also reported. In this study, ZnO nano particles and polycaprolactone (PCL) were blended to form composites using melt blending technique. The composites were employed to study the effect of nano inclusion on the materials. Further analysis was done using FTIR to investigate the band positions and absorption peak of the prepared samples, SEM and EDX for the morphology and elemental composition of samples. The FTIR spectra indicated a strong interaction at the interface of the ZnO nano particles with the polymer matrix. Amongst other findings, it was confirmed that the dielectric constant increases as the ZnO nano content increases where the average values for the different compositions are 4.39, 4.14, 3.62, 3.31 and 3.21 from highest to lowest filler percentage respectively. The high dielectric properties of the composites makes it suitable for small microwave absorption devices

Interface Polarization Effect on Dielectric and Electrical Properties of Polyurethane (PU)/Polyaniline (PANI) Polymer Composites

2013 ◽  
Vol 770 ◽  
pp. 275-278 ◽  
Author(s):  
Chatchai Putson ◽  
Darika Jaaoh ◽  
Nantakan Muensit
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Polymer Composites ◽  
Conductive Polymer ◽  
Conductive Filler ◽  
Filler Concentration ◽  
Scanning Calorimetry ◽  
Interface Polarization

In this study conductive polymer composites of polyurethane (PU)/polyaniline (PANI) below the percolation threshold were prepared by using solution casting. The dispersion of the conductive PANI fillers within the PU matrix was investigated by scanning electron microscopy (SEM). The SEM results showed a relatively homogeneous dispersion of the PANI fillers within the polymeric matrix. The effects of filler concentration on the dielectric and electrical conductivity depend upon the interface between conductive filler and matrix. Dielectric properties and ac conductivity of polymer composites have been investigated at different frequencies (102 - 105 Hz). The results show that the dielectric constant, dielectric loss and the electrical conductivity are strongly dependent on the frequency. The dielectric constant and dielectric loss decreased, whereas electrical conductivity increased with increasing frequency. In addition, the dielectric constant and conductivity increase when concentration of PANI increased. Differential scanning calorimetry (DSC) presented an enhanced the glass transition temperature (Tg) of the polymer composite with increasing PANI fillers. A correlation of Tg and the interface polarization between the PANI fillers and PU matrix on dielectric properties was proposed.

scholarly journals Размерный эффект в нанокомпозитах на основе молекулярного сегнетоэлектрика бромида диизопропиламмония

2019 ◽  
Vol 61 (2) ◽  
pp. 273
Author(s):  
C.B. Барышников ◽  
А.Ю. Милинский ◽  
E.B. Чарная ◽  
И.В. Егорова
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Size Effects ◽  
Low Temperatures ◽  
Structural Phase ◽  
Theoretical Models ◽  
Temperature Hysteresis ◽  
And Diffusion

AbstractWe present the results of studies of the dielectric properties of nanocomposites based on Al_2O_3 oxide films with a pore size of 330 and 60 nm with particles of an organic ferroelectric diisopropylammonium bromide (C_6H_16BrN, DIPAB) introduced into the pores, aimed at determining the size dependences of phase transition parameters. A shift in the phase transition to low temperatures and diffusion of the transition are found, which become more significant for smaller pores. A broadening of the temperature hysteresis of the dielectric constant of nanocomposites during the phase transition was also observed. The decrease in the phase transition temperature in nanocomposites with DIPAB nanoparticles is consistent with theoretical models of the size effects on the structural phase transition.

Theory of microwave dielectric constant logging using the electromagnetic wave propagation method

Geophysics ◽  
1979 ◽  
Vol 44 (5) ◽  
pp. 969-986 ◽  
Author(s):  
R. (Bob) Freedman ◽  
John P. Vogiatzis
Keyword(s):  
Dielectric Constant ◽  
Wave Propagation ◽  
Dielectric Properties ◽  
Phase Shift ◽  
Plane Wave ◽  
Computer Experiments ◽  
Theoretical Models ◽  
Dielectric Constants ◽  
Mud Cake ◽  
Wave Propagation Method

The composite dielectric constants of earth formations at microwave frequencies are strongly dependent on formation water saturations and relatively independent of water salinities. Therefore, microwave frequency dielectric constant logging offers an attractive new electromagnetic (EM) method of formation evaluation. The EM wave propagation method of dielectric constant logging attempts to deduce the dielectric properties of earth formations from phase shift and attenuation measurements of EM field, which have been propagated in the formation. A device which utilizes this method of well logging has been proposed by Calvert (1974) and Rau (1976) in two recent U.S. patents. We discuss the basic physics underlying the operation of a device of this type and describe the plane wave procedure discussed by these authors for relating the phase shift and attenuation measurements made by such a device to the formation dielectric properties. This procedure is suspect, since it is based on an unrealistic plane wave model which fails to treat the radiation field correctly and ignores the presence of a layer of mud cake which separates the antenna pad from the formation. To determine the errors likely to be inherent in using this procedure in practice, we consider several simple theoretical models of an EM wave propagation tool. Computer experiments performed on these theoretical models indicate that the apparent formation traveltimes obtained by using this procedure are semiquantitatively accurate with relative errors less than five percent in most cases. For our theoretical models, correction plots or departure curves are demonstrated which enable one to deduce the true formation traveltimes, given the apparent values and a knowledge of the dielectric properties and thickness of the mud cake. The problems which remain if this new method of logging is to attain its full potential (e.g., the accurate determination of formation fluid saturations) are discussed.

Hybrid formation of graphene oxide–POSS and their effect on the dielectric properties of poly(aryl ether ketone) composites

2017 ◽  
Vol 41 (8) ◽  
pp. 3089-3096 ◽  
Author(s):  
Yaning Lu ◽  
Shuling Zhang ◽  
Zhi Geng ◽  
Kai Zhu ◽  
Menghan Zhang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Dielectric Properties ◽  
Polymer Matrix ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Aryl Ether ◽  
Covalent Functionalization ◽  
Aryl Ether Ketone ◽  
Ether Ketone ◽  
Oligomeric Silsesquioxane

Covalent functionalization of graphene oxide with aminopropylisobutyl polyhedral oligomeric silsesquioxane efficiently reduced the dielectric constant of the polymer matrix.

Tuning the mechanical and dielectric properties of zinc incorporated hydroxyapatite

2020 ◽  
Vol 16 ◽  
Author(s):  
Alliya Qamar ◽  
Rehana Zia ◽  
Madeeha Riaz
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bone Growth ◽  
Healing Process ◽  
Secondary Phase ◽  
Chemical Precipitation ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Low Frequencies ◽  
A Minor

Background: Hydroxyapatite is similar to bone mineral in chemical composition, has good biocompatibility with host tissue and bone. Objective: This work aims to tailor the mechanical and dielectric properties of hydroxyapatite with zinc sudstitution, to improve wearability of implant and accelerate the healing process. Method: Pure and zinc incorporated hydroxyapatite Ca10(PO4)6(OH)2 samples have been successfully prepared by means of the chemical precipitation method. Results: The results showed that hydroxyapatite(Hap) having hexagonal structure was the major phase identified in all the samples. It was found that secondary phase of β-tricalcium phosphate (β-TCP) formed due to addition of Zinc resulting in biphasic structure BCP (Hap + β-TCP). A minor phase of ZnO also formed for higher concentration of Zn (Zn ≥ 2mol%) doping. It was found that the Zn incorporation to Hap enhanced both mechanical and dielectric properties without altering the bioactive properties. The microhardness increased upto 0.87 GPa for Zn concentration equal to 1.5mol%, which is comparable to the human bone ~0.3 - 0.9 GPa. The dielectric properties evaluated in the study showed that 1.5 mol% Zn doped hydroxyapatite had highest dielectric constant. Higher values of dielectric constant at low frequencies signifies its importance in healing processes and bone growth due to polarization of the material under the influence of electric field. Conclusion: Sample Z1.5 having 1.5 mol% Zn doping showed the most optimized properties suitable for bone regeneration applications.

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