Mi Yan, Peng Yiqin, Liu Wentao, Deng Lei, Shu Benxiang
State Key Laboratory of Power Transmission Equipment Technology, School of Electrical Engineering, Chongqing University, Chongqing 400044, China.
Micromachines (Basel). 2025 Mar 30;16(4):413. doi: 10.3390/mi16040413.
The electric field orientation method effectively promotes the orientation and arrangement of BN nanosheets, forming a thermal conduction network and enhancing the thermal conductivity of the composite material. In this study, microsecond pulsed electric field and direct current electric field were applied to induce the orientation and arrangement of BN nanosheets and improve the thermal conductivity of epoxy resin composites. Under a microsecond pulsed electric field of 50 Hz, 1.5 μs, and 8 kV/mm, the average orientation angle of BN nanosheets increased by 147.7%, and the thermal conductivity of the composite reached 0.352 W/(m·K), which is 1.84 times that of pure epoxy resin. In contrast, under a DC electric field of 70 V/mm, the average orientation angle of BN nanosheets increased by only 57.9%, while the thermal conductivity of the composite reached 0.364 W/(m·K), 1.91 times that of pure epoxy resin. The results indicate that the microsecond pulsed electric field primarily enhances the local orientation of the fillers to improve thermal conductivity, whereas the DC electric field mainly enhances the global arrangement of the fillers to achieve a similar effect. Additionally, thermogravimetric analysis and differential scanning calorimetry were conducted to evaluate the thermal properties of the composites. The results demonstrate that after BN nanosheets orientation and arrangement within the epoxy resin induced by both microsecond pulsed and DC electric fields, the composites exhibited a higher glass transition temperature and improved thermal stability. This study systematically explores the effects of microsecond pulsed and DC electric fields on filler orientation and arrangement, providing valuable insights for the fabrication of electric field-oriented composites.
电场取向法有效地促进了氮化硼纳米片的取向和排列，形成了热传导网络并提高了复合材料的热导率。在本研究中，施加微秒脉冲电场和直流电场以诱导氮化硼纳米片的取向和排列，并提高环氧树脂复合材料的热导率。在50Hz、1.5μs和8kV/mm的微秒脉冲电场下，氮化硼纳米片的平均取向角增加了147.7%，复合材料的热导率达到0.352W/(m·K)，是纯环氧树脂的1.84倍。相比之下，在70V/mm的直流电场下，氮化硼纳米片的平均取向角仅增加了57.9%，而复合材料的热导率达到0.364W/(m·K)，是纯环氧树脂的1.91倍。结果表明，微秒脉冲电场主要增强填料的局部取向以提高热导率，而直流电场主要增强填料的整体排列以达到类似效果。此外，进行了热重分析和差示扫描量热法以评估复合材料的热性能。结果表明，在微秒脉冲电场和直流电场诱导环氧树脂内的氮化硼纳米片取向和排列后，复合材料表现出更高的玻璃化转变温度和改善的热稳定性。本研究系统地探索了微秒脉冲电场和直流电场对填料取向和排列的影响，为电场取向复合材料的制备提供了有价值的见解。
