scholarly journals Surface Charge Properties of Epoxy Composites under DC Voltage Affected by Surface and Bulk Conductivity

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 370
Author(s):  
Qian Wang ◽  
Xidong Liang ◽  
Ke Chen ◽  
Chao Wu ◽  
Shan Liu
Keyword(s):  
Electric Field ◽  
Surface Charge ◽  
Epoxy Resin ◽  
Electric Fields ◽  
Surface Resistivity ◽  
Resin Composites ◽  
Charge Accumulation ◽  
Electrode Structure ◽  
Epoxy Resin Composites ◽  
High Electric Fields

As DC transmission voltage increases, the DC wall bushing becomes longer, and a supporting insulator is introduced to keep the conductor straight. Under extremely high electric fields coupled with a thermal gradient, the surface charge of the supporting insulator may distort the field distribution and increase the risk of flashover. In this paper, surface potentials of three model epoxy resin composites were systematically investigated under varied voltage amplitudes, different voltage polarities and electric field distributions. The bulk and surface resistivity of the epoxy resin composites over a broad temperature range were measured to reveal the correlations between surface charge and such basic electrical parameters. The results indicate that the normal-dominated electric field plays the major role in charge accumulation. The processes of surface charge accumulation and dissipation are more closely related to the surface resistivity. As a result, the surface charge properties can be improved by optimizing the electrode structure and resistivity of the epoxy resin composites.

Improving Amorphous Selenium Photodetector Performance Using an Organic Semiconductor

2013 ◽  
Vol 543 ◽  
pp. 451-454 ◽  
Author(s):  
Shiva Abbaszadeh ◽  
Nicholas Allec ◽  
Karim S. Karim
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Short Pulse ◽  
Amorphous Selenium ◽  
Semiconductor Materials ◽  
Manufacturing Processes ◽  
Charge Accumulation ◽  
Dark Current Density ◽  
Large Area ◽  
High Electric Fields

In this paper, a thin layer of perylene tetracarboxylic bisbenzimidazole (PTCBI) is investigated as a potential hole-blocking contact in an a-Se photodetector. The behavior of the device was characterized as a function of electric field under light and dark conditions. It was found that the PTCBI layer permits operation at high electric fields (>>10 V/μm) while maintaining a dark current density below 200 pA/mm2. Short pulse experiments were performed to assure that charge accumulation at the organic/a-Se interface is negligible and does not reduce the electric field in the a-Se layer. The detector investigated uses a simple low temperature fabrication process based on widely available semiconductor materials that can be easily integrated into current large area digital imager manufacturing processes.

Effects of hygrothermal and thermal-oxidative ageing on the open-hole properties of T800/high-temperature epoxy resin composites with different hole shapes

2019 ◽  
Vol 32 (3) ◽  
pp. 306-315 ◽  
Author(s):  
Liang Xu ◽  
Yi He ◽  
Shaohua Ma ◽  
Li Hui
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Epoxy Resin ◽  
Failure Modes ◽  
Resin Composites ◽  
Physical Ageing ◽  
Hygrothermal Ageing ◽  
Open Hole ◽  
Epoxy Resin Composites ◽  
Oxidative Ageing

T800/high-temperature epoxy resin composites with different hole shapes were subjected to hygrothermal ageing and thermal-oxidative ageing, and the effects of these different ageing methods on the open-hole properties of the composites were investigated, including analyses of the mass changes, surface topography changes (before and after ageing), fracture morphologies, open-hole compressive performance, dynamic mechanical properties and infrared spectrum. The results showed that only physical ageing occurred under hygrothermal ageing (70°C and 85% relative humidity), and the equilibrium moisture absorption rate was only approximately 0.72%. In contrast, under thermal-oxidative ageing at 190°C, both physical ageing and chemical ageing occurred. After ageing, the open-hole compressive strength of the composite laminates with different hole shapes decreased significantly, but the open-hole compressive strength after thermal-oxidative ageing was greater than that after hygrothermal ageing. Among the aged and unaged laminates, the laminates with round holes exhibited the largest open-hole compressive strength, followed by those with the elliptical holes, square holes and diamond holes. The failure modes of the laminates were all through-hole failures. The unaged samples had a glass transition temperature ( T g) of 226°C, whereas the T g of the samples after hygrothermal ageing was 208°C, which is 18°C less than that of the unaged samples, and the T g of the samples after thermal-oxidative ageing was 253°C, which is 27°C greater than that of the unaged samples.

Investigation of space charge behavior in self-healing epoxy resin composites

2021 ◽  
Author(s):  
Muhammad Zeeshan khan ◽  
Muhammad Hamza Younes ◽  
Aurang Zaib ◽  
Umar Farooq ◽  
Asim khan ◽  
...  
Keyword(s):  
Space Charge ◽  
Epoxy Resin ◽  
Resin Composites ◽  
Self Healing ◽  
Epoxy Resin Composites
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