Effect of chemical corrosion on charge transport behaviour in epoxy/Al ₂ O ₃ nanocomposite irradiated by gamma ray

Abstract

Chemical corrosion and gamma-ray irradiation appeared with the loss of coolant accident may seriously threaten the safe operation of a nuclear power plant, where epoxy resin (ER)-based materials are widely used. It is urgent to study the effects of the corrosion and the irradiation on the electrical performance in an ER-based nanocomposite. In this work, ER/Al 2 O 3 nanocomposite samples with 0, 1, 3, 5-wt% nano Al 2 O 3 filler content were prepared at the thickness of 2 mm, and the total gamma irradiation dose was 0, 500, and 1000 kGy. The samples were chemically corroded in a boric acid solution (pH = 4.7) and a trisodium phosphate alkaline solution (pH = 11) at 60°C and 100°C for 48 h. Charge transport behaviour in the samples was derived from the surface potential decay method. In addition, the sample structures were characterised to analyse the corrosion mechanism in the solutions. The results indicated that the depth and the density of the trap showed a temperature-dependent manner associated with the corrosion. With the addition of appropriate content of the filler, the trap centre was deepened and the carrier mobility was limited even after the corrosion. It is found that the appearance of hydroxyl and carboxyl groups during corrosion, the interaction between the nanoparticle and the matrix and the crosslinking reaction caused by the irradiation are responsible for the variation in charge transport behaviour.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Effect of organophilic group of coupling agent on the electrical performance of Boron Nitride/meta‐aramid composite paper

“…A carrier trap is a phenomenological concept of the charge transport characteristics of a dielectric medium. The method of isothermal surface potential decay (ISPD) indicates that the characteristic parameters of the trap distribution, including the trap depth E T and the trap density I ( t ), can be calculated from the curves of the surface potential decaying [24] $$${E}_{\mathrm{T}}={k}_{\mathrm{B}}T\,\mathrm{ln}(vt)$$$ $$$I(t)=\left({\varepsilon }_{0}{\varepsilon }_{\mathrm{r}}/e{T}_{\mathrm{h}}\right)\cdot tdU/dt$$$ where k B is the Boltzmann constant. T is the temperature, and v is the charge escape frequency, which is 4.17 × 10 13 s −1 for a DC field.…”

“…A carrier trap is a phenomenological concept of the charge transport characteristics of a dielectric medium. The method of isothermal surface potential decay (ISPD) indicates that the characteristic parameters of the trap distribution, including the trap depth E T and the trap density I(t), can be calculated from the curves of the surface potential decaying [24]…”

Influence of DBD treated nano‐Al2O3 on thermal and electrical insulation properties of epoxy nanocomposites at high temperatures

“…Trap characteristics play an important role in the charge migration process, changing carrier mobility and conductivity and affecting surface potential characteristics 24 . According to the isothermal surface potential decay (ISPD) model, the trap energy level 25 and trap density 26 can be calculated by Equations () and (): where, E t is the trap energy level, k is the Boltzmann constant, T is the measurement temperature, γ is the vibration frequency of electrons, t is the time, and N ( E t ) is the trap density, ε 0 is the vacuum dielectric constant, ε r is the relative dielectric constant, f 0 ( E t ) is the initial electron occupancy, and the value is 1, δ is the thickness of the surface charge layer, d is the thickness of the sample, and q is the electron charge, V is the surface potential of the sample.…”

Insulating materials for realising carbon neutrality: Opportunities, remaining issues and challenges

“…The presence of aromatic groups in its molecular chain contributes to the great endurance to radiation induced degradation [224]. Aromatic groups contained epoxy resin is modified via nano‐alumina (n‐Al 2 O 3 ) to withstand the gamma‐ray radiation and chemical corrosion that would emerge with the occurrence of loss of coolant accident (LOCA) [225], which reveals the effectiveness of inorganic nano‐particle and aromatic group against the harsh condition in NPP.…”