A multi-core model, i.e. a simplified term of multi-layered core is proposed as working hypothesis to understand various properties and phenomena that polymer nanocomposites exhibit dielectrics electrical insulation. It gives fine structures what are called "interaction zones". An interfacial layer several tens nm multi-layered, which consists bonded layer, bound loose layer. In addition, the Gouy-Chapman diffuse with Debye shielding length 100 superimposed in cause far-field effect....

Polymer nanocomposites possess promising high performances as engineering materials, if they are prepared and fabricated properly. Some work has been recently done on such polymer dielectrics electrical insulation. This was reviewed in 2004 based the literatures published up to 2003. New significant findings have added since then. Furthermore, a multi-core model with far-distance effect, which is closely related an "interaction zones", proposed from consideration of mesoscopic analysis...

Polymer nanocomposites are defined as polymers in which small amounts of nanometer size fillers homogeneously dispersed by only several weight percentages. Addition just a few percent the nanofillers has profound impact on physical, chemical, mechanical and electrical properties polymers. Such change is often favorable for engineering purpose. This nanocomposite technology emerged from field plastics, potentially expanded its application to structural materials, coatings, packaging...

Abstract Dielectric polymer composites with high thermal conductivity are very promising for microelectronic packaging and management application in new energy systems such as solar cells light emitting diodes (LEDs). However, a well‐known paradox is that conventional usually suffer from the dielectric constant loss, while on other hand, composite materials excellent properties possess low conductivity. In this work, an ideal thermally conductive epoxy nanocomposite successfully fabricated...

The interface between filler and matrix has long been a critical problem that affects the thermal conductivity of polymer composites. effects on composite with low loading are well documented, whereas role in highly filled composites is not clear. Here we report systematic study epoxy Six kinds surface treated as received AlN particles used fillers. Three functionalized by silanes, i.e., amino, epoxy, mercapto group terminated silanes. Others three materials, polyhedral oligomeric...

Dielectric polymer composites with high dielectric constants and thermal conductivity have many potential applications in modern electronic electrical industry. In this study, three-phase comprising poly(vinylidene fluoride) (PVDF), barium titanate (BT) nanoparticles, β-silicon carbide (β-SiC) whiskers were prepared. The superiority of method is that, when compared the two-phase PVDF/BT composites, not only show significantly increased but also higher conductivity. Our results that addition...

In this short review, we discussed some aspects of nanocomposites regarding electrical tree growth and breakdown. It appears that nanoparticles, properly mixed dispersed in the polymer matrix, increase breakdown strength hinder trees nanocomposite. Nanoparticles act as barriers obstructing delaying dielectric This article also put forward a tentative proposal for mechanisms treeing nanocomposites.

This paper focuses on the electrical insulation properties of a newly prepared composite material by nano- and micro-filler mixture. Nano- mixture composites were made dispersing nano-scale layered silicate fillers micro-scale silica in epoxy resin. To investigate effects mixture, thermal expansion coefficient breakdown needle-plate electrode method measured for filler conventional filled epoxy. The had almost same as In continuous voltage rising test, 7% higher strength than Moreover, under...

Partial discharge (PD) degradation of polyamide both without nanoscale fillers (nanofillers) and with 2,4 5 wt% additions nanofillers was investigated. Such materials were subjected to PDs using the IEC (b) electrodes for evaluation. Comparisons made as surface roughness observed by scanning electron microscopy atomic force microscopy. It found that change in is far smaller specimens than those nanofillers, 2 addition sufficient improvement roughness. Furthermore, it elucidated difference...

Novel polyaniline decorated reduced graphene oxide (rPANI@rGO) two-dimensional (2D) hybrids sheets were successfully prepared by in situ polymerization of aniline on (GO) and successive reduction hydrazine. PANI is heavily reduced, thus it electrically insulating. The hybrid used as a novel filler for high performance poly(methyl methacrylate) (PMMA) nanocomposites. Our results show that, when compared with the PMMA/rGO composites, PMMA/rPANI@rGO nanocomposites not only dielectric constant...

Nanodielectric materials with high dielectric constant, low loss, and energy storage capability are highly desirable in modern electric electronics industries. It has been proved that the preparation of core-shell structured polymer nanocomposites via "grafting from" method is an effective approach to these materials. However, by using this approach, deep understanding structure-dielectric property relationship nanodielectrics limited because lack detailed information (e.g., molecular...

Advances in polymer nanodielectrics over the past 50 years, using colloid science, composite technology, and nanotechnology, are reviewed. Despite rapid progress during 10 interdisciplinary investigation is needed to yield additional benefit society.

Frequency accelerated partial discharge (PD) aging of epoxy nanocomposite with 5 wt % additions clay was investigated in comparison that without terms PD erosion depth. It found the change depth is far smaller specimens than those clay. The newly developed organic modification and solubilization methods give comparable resistance characteristics. latter would be more resistant to PD's former, if were prepared properly. clarified nano-micro mixed composites superior single nanocomposite. Nano...

It is often observed that the insulation structure for an insulated gate bipolar transistor (IGBT) suffers from dielectric failure, when made of epoxy resin to which micro fillers with a high thermal conductivity were added. In order reveal above phenomena and clarify breakdown (BD) mechanism, we have carried out experiments using MB-PWB (metal-base printed wiring board) simulated structure. As result, it was clarified IGBT breaks down after successive partial discharges (PDs). also...

Initiation of electrical treeing in polyethylene is discussed with the emphasis a charge injection and extraction process, which considered to feature incubation period during there are no apparently visual change detectable partial discharges. Some evidences for process shown by electrical, thermal optical liberation injected from metal electrode into polyethylene. Effects work functions on tree formation demonstrated. On basis above find- ings, field emission equi-energy theory proposed...

Partial discharge (PD) pulses are considered to be generated after application of overvoltage across a cavity. Their magnitude is proportional the n-th power overvoltage. It decreases with an increase in cavity space and moisture content. Very long time lags for PD inception, such as even day, was confirmed. This phenomenon associated PD's statistical lag number free electrons gas (O2, N2). Oxygen nitrogen exhibit their distinctive features. Nitrogen generate swarming micro pulses, while...

Dielectric polymer nanocomposites with high dielectric constant have wide applications in energy density electronic devices. The introduction of ceramic nanoparticles into a represents an important route to fabricate constant. However, the prepared by this method generally suffer from relatively low breakdown strength and loss, which limit further increase efficiency nanocomposites. In contribution, using core–satellite structured ultra-small silver (Ag) decorated barium titanate (BT)...

The aim of this research is to find a way achieve the epoxy composites with both high thermal conductivity and acceptable dielectric breakdown (BD) strength. As conductivity, low permittivity expansion coefficient filler can endow composite higher BD strength lower respectively, BN (boron nitride) was adopted as main in research. Thermal investigated part. samples will be discussed Part II. Neat other 25 kinds epoxy/BN were prepared by hot press method. Most fillers surface modified silane...

High dielectric constant polymer composites capable of withstanding a high electrical field have much application in electronic devices and equipment because their ease processing, flexibility, low cost. Conventional with constant, namely ceramic particulate conductive filler based percolative composites, either show enhancement or cannot withstand electric field. Here we report new strategy for preparing by using novel three-dimensional zinc oxide (3D ZnO) superstructures as fillers. Two...

A novel route to prepare core-shell structured nanocomposites with excellent dielectric performance is reported. This approach involves the grafting of polystyrene (PS) from surface BaTiO(3) by an in situ RAFT polymerization. The PS/BaTiO(3) not only show significantly increased constant and very low loss, but also have a weak frequency dependence properties over wide range frequencies. In addition, can be easily tuned varying thickness PS shell. Our method promising for preparing...

Reduction of graphene oxide is primarily important because different reduction methods may result in with totally properties. For systematically exploring the oxide, studies temperature-dependent electrical properties (GO) are urgently required. In this work, for first time, broadband dielectric spectroscopy was used to carry out an situ investigation on transition GO paper from −40 150 °C. The results clearly reveal a very interesting four-stage increasing temperature: insulator below 10 °C...

Aging of polymeric and composite materials is reviewed mainly from the standpoint their interfacial performance. Insulating can be divided into simple polymers composites. Polymers for power cables, transformers, insulators rotating machines consist thermoplastics such as PE, PET PPS, elastomers silicone, EPR EPDM, thermosets epoxy. Composites GIS, comprise epoxy/glass, epoxy/silica/alumina, epoxy/mica systems. processes are complicated in general, take place under simultaneous multiple...

A computer-aided measurement system has enabled novel interpretation of partial discharge (PD) signals. We take into consideration voltage phase-angle at which each PD pulse takes place, and consequently need simultaneous the height q phase angle ϕ. According to analysis signals, close relation between signals insulation degradation or defects was found. New characteristics such as 4-q distribution profile (average versus angle) can detect growth electrical trees in caused by PDs. The...

Effects of nanofiller materials on typical dielectric properties bisphenol-A epoxy resin were compared among three kinds nanofillers, i. e. boehmite alumina, titania, and silica. In all the samples, complex permittivity ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ' " become significantly higher with an increase in temperature beyond 120 °C, especially at low frequencies. Such indicates abundance mobile charge carriers, which was...