Influence of hierarchy structure on electrical properties of gradient-distribution aluminum oxide/polyethylene nanocomposites

Abstract

In the recent decades, the phenomena of space charge accumulation in the high voltage direct current (HVDC) insulation have attracted more and more attention. In this paper, the gradient-distribution multi-layered Al 2 O 3 /low density polyethylene (LDPE) nanocomposites were prepared via layer-by-layer melting blending and hot pressing method. Morphologies and electrical properties of these gradient-distribution structured composites were discussed. Results showed that this unique structure could largely enhance the breakdown strength of LDPE. The breakdown strength of the LDPE nanocomposites varied with nano-Al 2 O 3 concentrations, and it could reach to 200 kV/mm for the LDPE nanocomposites.Besides, space charge of the LDPE nanocomposites was measured by pulsed electro-acoustic (PEA) method. The charge profiles indicated that space charge suppression of the gradient-distribution multi-layered composites was better than that of the monolayer ones with general mean-distribution structure. Their excellent insulating properties were attributed to the trap which exists in the surface, and that could well inhibit the charge injecting into the materials.

Influence of Ungrafted Monomers in Graft Copolymers on Electrical Insulating Properties of Polyethylene

“…This phenomenon is attributed to the thermal motion of the molecular chains. After heating at 65 °C for 24 h, the molecule rearrangement took place toward the more stable conformations, which resulted in increased DC breakdown strength . After the accelerated migration time exceeds 48 h, the dielectric strength of all samples tends to be steady, indicating that PE/PE- g -AA and PE/u-PE- g -AA blends possess stable and reliable long-time electrical properties.…”

An improved polarization model to analyze the breakdown strength of nano‐liquid under impulse breakdown test

“…For ease of analysis, we assumed that the nanoparticles were spherical. In the absence of an applied electric field, we can calculate the attractive potential V A and the repulsive potential V R under the van der Waals and electric doublelayer forces [15,[19][20][21][22]:…”

A metrologically traceable protocol for the quantification of trace metals in different types of microplastic

“…Therefore, TiO 2 , used as white opacifier [78] or TiO 2 nanoparticles as reinforcing components [79,80] can be suspected as Ti source. Concerning Al, it has been shown that Al 2 O 3 is used as a functional filler to enhance LDPE's dielectric resistance [81,82].…”