Field-Gradient-Driven Molecular Polarization and Trap-State Modulation in Cross-Linked Polyethylene Dielectrics

Area of Science:

• Materials Science
• Electrical Engineering
• Polymer Science

Background:

• Electrical failure in cross-linked polyethylene (XLPE) insulation is initiated by microdefects causing localized high electric fields.
• Understanding charge-field interactions is crucial for enhancing the electrical reliability of polymer dielectrics.

Purpose of the Study:

• To develop a molecular targeting strategy for stabilizing microdefects in XLPE insulation.
• To investigate the mechanism of field-driven molecular redistribution and its effect on electrical properties.

Main Methods:

• Utilized a dielectrophoresis-guided molecular targeting strategy to direct anthraquinone (AQ) to high-field regions within XLPE.
• Analyzed the impact of AQ on local fields, carrier capture, trap states, and conductivity.

Main Results:

• Optimal 1 wt % loading of AQ enhanced the direct current breakdown strength of XLPE by 44%.
• AQ addition reduced conductivity and regulated trap states, suppressing field distortion.
• Demonstrated field-driven molecular redistribution and trap-state regulation as a coupled mechanism.

Conclusions:

• The dielectrophoresis-guided molecular targeting strategy effectively stabilizes defects in XLPE insulation.
• This approach offers new insights into charge-field dynamics in polymer dielectrics.
• Established a generalizable mechanism for defect stabilization via dielectrophoretic targeting in polymer insulation.