PDA@BNNS Epoxy Composite

36% less space charge

Targeting space charge accumulation in HVDC insulation, this composite employs polydopamine-functionalized boron nitride nanosheets to introduce deep traps, achieving synergistic regulation of charge dynamics via multiple mechanisms.

Dai, Chao · Zheng, Zhang · Nailong, Liu · Xiangzhuo, Kong · Ding, Man · Yuanxiang, Zhou · Huang, Meng · Paramane, Ashish Sharad

Applied Physics Letters 2026

Specifications

Space charge reduction

{'zh': '36', 'en': '36'} %

Effective charge injection barrier

{'zh': '1.35', 'en': '1.35'} eV

Conduction activation energy

{'zh': '0.70', 'en': '0.70'} eV

Advantages

Significantly reduced space charge

The 3 wt.% PDA@BNNS composite reduces stored charge by approximately 36% at 20 kV/mm compared to pure epoxy, attributed to deep traps capturing injected charges.

Higher charge injection barrier

The effective charge injection barrier increases from 1.12 eV to 1.35 eV, hindering charge injection from electrodes.

Modified conduction mechanism

Conduction activation energy rises to 0.70 eV, and charge transport transitions to three-dimensional variable-range hopping dominated by deep traps, altering the bulk conduction mechanism.

Applications

• HVDC insulation：Suppresses space charge to extend HVDC cable insulation life
• Dielectric materials：Provides deep-trap modification for optimized charge transport