The effect of loading ratios and electric field on charge dynamics in silica-based polyethylene nanocomposites. (23rd August 2018)

• Record Type: Journal Article
• Authors: Wang, Yan; Qiang, Dayuan; Xu, Zhiqiang; Chen, George; Vaughan, Alun
• Is Part Of: Journal of physics. Volume 51:Number 39(2018)
• Publication Date: 2018-08-23
• Subjects: nanodielectrics -- nanocomposites -- space charge -- surface potential decay -- tunnelling process -- deep traps -- nanosilica; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aad7e8
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Nanodielectrics have been expected to improve the electrical performance and are considered as dielectrics for the future. It has been recognized that the electrical performance is closely related to charge dynamics in the dielectrics material. However, the mechanism of charge dynamics in the interphase of nanodielectrics has not been fully understood, which causes difficulty in understanding the effect of nanoparticle loading ratios and electric fields applied on the electrical properties. Recently, a model based on the tunneling process with the presence of deep traps has been suggested as one conceivable candidate for explaining charge dynamics in nanodielectrics, but the related experiment results are not discussed with the tunnelling process. In this paper, the measurements including isothermal surface potential decay and space charge are conducted for the blend polyethylene incorporated with the untreated silica nanocomposites. According to the experimental observation compared with the unfilled blend polyethylene, the electrical properties of nanocomposites with high loading ratios of 2 wt%, 5 wt% and 10 wt% are worsened, such as facilitated space charge accumulation and injection, and faster charge carriers transport. On the other hand, regarding the nanocomposites with the low loading ratios of 0.5 wt%, slow transport of charge carriers, and suppressed space charge accumulation and injection were observed. The effect of the lower and higher electric field on the electrical properties of the nanocomposites was similar for the low and high loading ratios. The tunnelling process associated with deep traps can effectively explain these observed phenomena of nanocomposites, it is therefore suggested for further explaining the electrical properties and charge dynamics in the nanodielectrics.