scholarly journals Electric Field Grading Material Based on Thermally Reduced Graphene Oxide

2017 ◽  
Author(s):  
W. Li ◽  
U. W Gedde ◽  
H. Hillborg
Keyword(s):  
Graphene Oxide ◽  
Electric Field ◽  
Reduced Graphene Oxide ◽  
Electric Fields ◽  
Silicone Rubber ◽  
Rubber Matrix ◽  
Reduced Graphene ◽  
Rubber Composite ◽  
Non Linear ◽  
A Minor

<p>Silicone rubber filled with low amounts of thermally<br />reduced graphene oxide exhibit non-linear conductivity<br />with exposed to increased electric fields. Such material<br />can be interesting as electric field grading material in<br />HVDC cable accessories. In this study graphene oxide<br />was thermally reduced (rGO) at 120 and 180 °C during<br />12 hours in a hot air oven. The reduction was confirmed<br />by TGA and FTIR. 3 wt.% rGO was then dispersed in a<br />silicone rubber matrix and homogenous dispersion was<br />demonstrated by the scanning electron microscopy. The<br />rGO-filled silicone rubber (120 and 180 °C reduced)<br />exhibited a non-linear resistivity when exposed to an<br />increasing electric (DC) field. The conductivity<br />decreased from 10^14 to 10^11 Ohm m when the electric<br />field increasing from 0.2 to 6 kV/mm. The onset of the<br />non-linear conduction occurred in the range of 1 – 2<br />kV/mm. The long-term stability of the conductivity of<br />the silicone rubber composite was tested. After 47 days<br />ageing at 120 °C, therGO/silicone rubber composite<br />exhibited a slight increase in the onset of non-linear<br />conduction, as well as a minor increase in resistivity.</p>

scholarly journals Gas sensors based on dielectrophoresis of graphene, and graphene oxide, and reduced graphene oxide A Review

2020 ◽  
Author(s):  
shamim Azimi
Keyword(s):  
Graphene Oxide ◽  
Electric Field ◽  
Reduced Graphene Oxide ◽  
Electric Fields ◽  
Surrounding Medium ◽  
Diagnostic Technique ◽  
Environmental Research ◽  
Label Free ◽  
Reduced Graphene ◽  
Electrode Edge

Dielectrophoresis (DEP) is a label-free, accurate, fast, and low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. DEP occurs when uncharged particles in the solution are subject to a spatially non-uniform alternating-current (AC) electric field, resulting in the motion of particles by creating a polarizability gradient between the particles and the suspending medium. The movement of particles in DEP is based on the difference in polarizability between the particles and the surrounding medium. If the particles move toward the electrode edge, the region of high electric field gradient, the response is called positive DEP (p-DEP). At the same time, if the particles move away from the electrode edge, the response is called negative DEP (n-DEP). This phenomenon provides a powerful and versatile tool for the non-destructive manipulation of nanoscale materials, allowing for the control of the resistance and the type of the assembly. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, sensors, biosensors, microfluidics, medicine, and diagnostics. This paper reviews the fundamentals of DEP and its specific application in the incorporation of graphene, graphene oxide(GO), and reduced graphene oxide(RGO), enabling the assembly of individual two-dimensional nanostructures at predefined locations in microdevices for gas sensor applications. The review provides an essential framework for parallel fabrication approaches of graphene-based devices.

scholarly journals A reduced graphene oxide–borate compound-loaded melamine sponge/silicone rubber composite with ultra-high dielectric constant

RSC Advances ◽  
2019 ◽  
Vol 9 (25) ◽  
pp. 14276-14285
Author(s):  
Hong Zhang ◽  
Chuan-Guo Ma ◽  
Pei-Bang Dai ◽  
Jian Zhang
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Silicone Rubber ◽  
High Dielectric Constant ◽  
Reduced Graphene ◽  
Rubber Composite ◽  
High Dielectric ◽  
Borate Compound

A reduced graphene oxide–borate compound-loaded melamine sponge/silicone rubber composite with the ultra-high dielectric constant of 2.71 × 104.

scholarly journals Dielectric Polarization and Electrorheological Response of Poly(ethylaniline)-Coated Reduced Graphene Oxide Nanoflakes with Different Reduction Degrees

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2528
Author(s):  
Yudong Wang ◽  
Min Yang ◽  
Honggang Chen ◽  
Xiaopeng Zhao ◽  
Jianbo Yin
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electric Fields ◽  
Flow Instability ◽  
Interfacial Polarization ◽  
Simultaneous Action ◽  
Dielectric Polarization ◽  
Polarization Rate ◽  
Reduced Graphene ◽  
The Difference

We prepared poly(ethylaniline)-coated graphene oxide nanoflakes and then treated them with different concentrations of hydrazine solution to form dielectric composite nanoflakes having different reduction degrees of reduced graphene oxide core and insulating polyethylaniline shell (PEANI/rGO). The morphology of PEANI/rGO was observed by scanning electron microscopy, while the chemical structure was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer. The influence of reduction degrees on the conductivity, dielectric polarization and electrorheological effect of PEANI/rGO in suspensions was investigated by dielectric spectroscopy and rheological test under electric fields. It shows that the PEANI/rGO has two interfacial polarization processes respectively due to rGO core and PEANI shell. As the number of hydrazine increases, the conductivity and polarization rate of rGO core increase. As a result, the difference between the polarization rate of rGO core and that of the PEANI shell gradually becomes large. This increased difference does not significantly decrease the yield stress but causes the flow instability of PEANI/GO suspensions under the simultaneous action of electric and shear fields.

Reduced Graphene Oxide for Room Temperature Hydrogen Storage Application

2015 ◽  
Vol 1086 ◽  
pp. 91-95 ◽  
Author(s):  
A. Venkatesan ◽  
Raj Nanalal Patel ◽  
E.S. Kannan
Keyword(s):  
Graphene Oxide ◽  
Electric Field ◽  
Hydrogen Storage ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Structural Defects ◽  
Back Gate ◽  
Hot Air ◽  
Reduced Graphene ◽  
P Type

Graphene oxide (GO) is extracted from graphite oxide synthesized using modified Hummers method. The extracted GO solution is then drop casted onto a p type silicon substrate and dried in hot air oven. The dried solution is annealed at a temperature of about 200 degree Celsius for about one hour to obtain thermally reduced graphene oxide (RGO). Such thermally synthesized RGO usually have a lot of structural defects which can act as a binding site for hydrogen. The binding efficiency of hydrogen to defect centers can be increased by applying electric field to RGO as it changes the carrier concentration (doping) on the surface. This induces more polarization in the hydrogen molecule resulting in strong binding force, thereby increasing its hydrogen storage efficiency. In our experiment we have demonstrated room temperature electric field doping in RGO films by modulating the channel current by changing the back gate voltage which is a precursor for employing RGO in hydrogen storage applications.KeywordsGraphene oxide, Reduced graphene oxide, Field effect, Hydrogen storage, and Defects

Electric field-induced nanopatterning of reduced graphene oxide on Si and a p–n diode junction

2011 ◽  
Vol 21 (15) ◽  
pp. 5805 ◽  
Author(s):  
Sohyeon Seo ◽  
Changhua Jin ◽  
Young Rae Jang ◽  
Junghyun Lee ◽  
Seong Kyu Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electric Field ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene

scholarly journals Reduced Graphene Oxide Embedded with MQ Silicone Resin Nano-Aggregates for Silicone Rubber Composites with Enhanced Thermal Conductivity and Mechanical Performance

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1254 ◽  
Author(s):  
Weijie Liang ◽  
Xin Ge ◽  
Jianfang Ge ◽  
Tiehu Li ◽  
Tingkai Zhao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Silicone Rubber ◽  
Heat Dissipation ◽  
Mechanical Performance ◽  
Thermal Interface Material ◽  
Silicone Resin ◽  
Blending Method ◽  
Reduced Graphene

With developments of the electronics industry, more components are being included in electronic devices, which has led to challenges in thermal management. Using reduced graphene oxide embedded with MQ silicone resin (RGO/MQ) nano-aggregates as the composite filler and silicone rubber (SR) as the matrix, a simple approach is designed to prepare RGO/MQ/SR composites. Reduced graphene oxide (RGO) was first used as a substrate for the growth of MQ silicone resin by hybridization, forming sandwich-like micro structured RGO/MQ nano-aggregates successfully. Then, RGO/MQ was integrated into α,ω-dihydroxylpolydimethylsiloxane based on the in situ solvent-free blending method, followed by condensation and vulcanization, fabricating the final RGO/MQ/SR composites. The effective strategy could enhance the adaptability between graphene and silicone matrix under external stimuli at room temperature by embedding nanoscale MQ into the interface of graphene/silicone as the buffer layer. Obvious improvements were found in both thermal conductivity and mechanical properties due to excellent dispersion and interfacial compatibility of RGO/MQ in the host materials. These attractive results suggest that this RGO/MQ/SR composite has potential as a thermal interface material for heat dissipation applications.

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