scholarly journals Improvement of Dielectric Breakdown Performance by Surface Modification in Polyethylene/TiO2 Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3346 ◽  
Author(s):  
Weiwang Wang ◽  
Shengtao Li
Keyword(s):  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Interface Region ◽  
Insulation System ◽  
Polar Groups ◽  
Deep Traps ◽  
Relaxation Polarization ◽  
Surface Modified ◽  
Shallow Traps ◽  
Surface Chemical Modification

Dielectric breakdown is a significant property for the insulation system in high voltage power equipment. This paper is dedicated to the improvement of dielectric breakdown by surface-functionalized nanoparticles in low-density polyethylene (LDPE). Prior to the preparation of LDPE/TiO2 nanocomposites, the nanoparticles were surface modified by the silane coupling followed by the chemical reaction process. Results of Fourier transform infrared spectroscopy (FTIR) indicated that some polar groups and chemical bonding were introduced on the surface of TiO2 nanoparticles. A reduction of dielectric permittivity was observed at low nanoparticle loading (<2 wt%) samples, which responded to the restriction of the molecular chain in the interface region. High nanoparticle loadings (2 wt%, 5 wt%, 10 wt%) introduced an obvious relaxation polarization. The trap parameters detected by the thermally stimulated current (TSC) method indicated that the deep traps were introduced by small amounts of nanoparticles (≤2 wt%), while more shallow traps occurred in high loading (5 wt%, 10 wt%) samples. Meanwhile, the increase of breakdown strength at low loading samples were closely related to the deep traps, which was ascribed to the interface region by surface chemical modification.

scholarly journals Improved Dielectric Properties of Thermoplastic Polyurethane Elastomer Filled with Core–Shell Structured PDA@TiC Particles

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3341
Author(s):  
Xinfu He ◽  
Jun Zhou ◽  
Liuyan Jin ◽  
Xueying Long ◽  
Hongju Wu ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Thermoplastic Polyurethane ◽  
Low Loss ◽  
Elongation At Break ◽  
The Matrix ◽  
Potential Applications ◽  
Low Levels ◽  
Surface Modified ◽  
Dielectric And Mechanical Properties

Insulating interlayer between nanoparticles and polymer matrix is crucial for suppressing the dielectric loss of polymer composites. In this study, titanium carbide (TiC) particles were surface modified by polydopamine (PDA), and the obtained PDA@TiC powders were used to reinforce thermoplastic polyurethane (TPU). The results indicate that the PDA@TiC were homogenously dispersed in the matrix compared with the pristine TiC, and that the PDA@TiC/TPU composites show improved dielectric and mechanical properties, i.e., much lower dissipation factors and obviously enhanced dielectric breakdown strength, as well as higher tensile strength and elongation at break as compared to the raw TiC/TPU. The nanoscale PDA interlayer contributes to the dielectric and mechanical enhancements because it not only serves as an insulating shell that prevents TiC particles from direct contacting and suppresses the loss and leakage current to very low levels, but also enhances the interfacial interactions thereby leading to improved mechanical strength and toughness. The prepared flexible PDA@TiC/TPU with high permittivity but low loss will find potential applications in electronic and electrical applications.

Consequences of Silicon Segregation on the Dielectric Properties of Sintered Alumina

2006 ◽  
Vol 249 ◽  
pp. 281-0 ◽  
Author(s):  
Kamel Zarbout ◽  
Gérard Moya ◽  
Jean Bernardini ◽  
Denise Moya-Siesse ◽  
A. Si Ahmed ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Positron Lifetime ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Impurity Content ◽  
Impurity Level ◽  
Dielectric Breakdown Strength ◽  
High Impurity ◽  
Potential Traps ◽  
Shallow Traps

The dielectric breakdown strengths of two series of sintered alumina samples of low and high impurity content (where Si is the dominant element with, respectively, 90 and 1500 ppm) and impurity level (25 ppm of Si and 12 ppm of Ti) are compared with positron lifetime measurements. The dielectric breakdown strength of sintered alumina is found higher than that of single crystal. This improvement is stronger when silicon is the only major foreign element. If, in addition to SiO2, MgO and CaO are present in substantial amounts, the improvement is lessened. This is attributed to the enhanced bulk solubility of Si. These results are discussed by calling for the potential traps for positrons and electrons that are located at grain boundaries. It is deduced that the improvement of the dielectric breakdown strength stems from the consequences of Si segregation at grain boundaries via electron trapping in shallow traps, which are likely the x '' Al • Al ) V : (3Si clusters.

scholarly journals Dielectric Breakdown Strength and Energy Storage Density of CCTO-ZBS Electroceramic

2020 ◽  
Vol 596 ◽  
pp. 012006
Author(s):  
Muhammad Qusyairie Saari ◽  
Julie Juliewatty Mohamed ◽  
Muhammad Azwadi Sulaiman ◽  
Mohd Fariz Abd Rahman ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Energy Storage Density ◽  
Dielectric Breakdown Strength ◽  
Storage Density

scholarly journals Construction of a Three-Dimensional BaTiO3 Network for Enhanced Permittivity and Energy Storage of PVDF Composites

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3585
Author(s):  
Xueqing Bi ◽  
Lujia Yang ◽  
Zhen Wang ◽  
Yanhu Zhan ◽  
Shuangshuang Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Polyvinylidene Fluoride ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Sol Gel ◽  
Three Dimensional ◽  
Low Dielectric ◽  
Energy Storage Properties ◽  
Discharge Energy Density ◽  
Pure Pvdf

Three-dimensional BaTiO3 (3D BT)/polyvinylidene fluoride (PVDF) composite dielectrics were fabricated by inversely introducing PVDF solution into a continuous 3D BT network, which was simply constructed via the sol-gel method using a cleanroom wiper as a template. The effect of the 3D BT microstructure and content on the dielectric and energy storage properties of the composites were explored. The results showed that 3D BT with a well-connected continuous network and moderate grain sizes could be easily obtained by calcining a barium source containing a wiper template at 1100 °C for 3 h. The as-fabricated 3D BT/PVDF composites with 21.1 wt% content of 3D BT (3DBT–2) exhibited the best comprehensive dielectric and energy storage performances. An enhanced dielectric constant of 25.3 at 100 Hz, which was 2.8 times higher than that of pure PVDF and 1.4 times superior to the conventional nano–BT/PVDF 25 wt% system, was achieved in addition with a low dielectric loss of 0.057 and a moderate dielectric breakdown strength of 73.8 kV·mm−1. In addition, the composite of 3DBT–2 exhibited the highest discharge energy density of 1.6 × 10−3 J·cm−3 under 3 kV·mm−1, which was nearly 4.5 times higher than that of neat PVDF.

Influence of Chromium Ions on the Dielectric Properties of the PbO-Ga2O3-P2O5 Glass System

2007 ◽  
Vol 62 (5-6) ◽  
pp. 315-323 ◽  
Author(s):  
Gnanaprakasm Little Flower ◽  
Maddireddy Srinivasa Reddy ◽  
Musugu Venkata Ramana Reddy ◽  
Nalluri Veeraiah
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Dielectric Properties ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Oxidation States ◽  
Optical Absorption Spectra ◽  
Dielectric Breakdown Strength ◽  
Chromium Ions ◽  
Wide Range

PbO-Ga2O3-P2O5 glasses containing different amounts of Cr2O3, ranging from 0 to 1.0 mol%, were prepared. The dielectric properties (viz., constant ε’, loss tanδ , ac conductivity σac over a wide range of frequencies and temperatures, dielectric breakdown strength) have been studied as a function of the concentration of chromium ions. An anomaly has been observed in the dielectric properties of these glasses, when the concentration of Cr2O3 is about 0.4 mol%. This anomaly has been explained in the light of different oxidation states of chromium ions with the aid of data of differential thermal analysis and optical absorption spectra of these glasses.

scholarly journals Size and temperature effects on dielectric breakdown of ferroelectric films

2020 ◽  
Author(s):  
Sheng Tong
Keyword(s):  
Energy Density ◽  
Electric Field ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Operating Temperature ◽  
Electric Energy ◽  
Ferroelectric Films ◽  
Lead Lanthanum Zirconate Titanate ◽  
Dimensional Parameters ◽  
Electric Energy Density

Abstract The paper introduces a model of dielectric breakdown strength. The model integrated thermal breakdown and defect models, representing the relationship between the electric field of ferroelectric films and dimensional parameters and operating temperature. This model is verified with experimental results of the lead lanthanum zirconate titanate (PLZT) films of various film thickness (d = 0.8 – 3 mm), electrode area (A = 0.0020 – 25 mm2) tested under a range of operating temperature (T = 300 – 400 K) with satisfying fitting results. Also learned is a relationship that the recoverable electric energy density is directly proportional to the square of breakdown electric field. This relationship is found viable in predicting the electric energy density in terms of variables of d, A, and T for the PLZT films.

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