摘要
Due to their outstanding electrical insulation performance,low energy loss and high reliability,polymer dielectrics are widely used in flexible electronics,capacitors and large-scale power transmission equipment[1–5].However,polymer dielectrics accumulate large amounts of charge on their surface during use,which causes local electric field distortion and induces flashover,explosion,and equipment damage[6–9].Although researchers have attempted to develop methods to reduce the accumulation of surface charge through material modification,such as plasma treatment[10],direct fluorination[11],and coating[7,9,12],each of these methods has drawbacks;thus,the bottleneck has yet to be overcome.
聚合物电介质在使用过程中表面会积聚大量的电荷,导致局部电场畸变、闪络、爆炸和设备损坏等问题.由于造成电荷积聚的聚合物载流子深陷阱的主要构成目前仍不清楚,这一瓶颈问题目前仍未得到有效解决.本文基于开尔文探针力显微镜(KPFM)和磁力显微镜(MFM)观测了纳米微区聚合物自由基的电荷行为,发现自由基表现出深陷阱的特性.第一性原理计算发现出现自由基后的体系中存在深能级缺陷态.微观和宏观的电荷测量表明,清除自由基后的聚合物表面电荷量显著减少,这为聚合物电介质在诸多领域中的安全使用提供了有效的材料改性方案.本文首次揭示了电介质中的自由基是深陷阱,为后续关于聚合物电介质的电荷特性方面的研究提供了重要的理论指导.
作者
Tianyu Wang
Xiaofen Li
Boya Zhang
Dayu Li
Jianbo Liu
Guixin Zhang
王天宇;李小芬;张博雅;李大雨;刘剑波;张贵新(State Key Laboratory of Control and Simulation of Power System and Generation Equipment,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;Key Laboratory of Advanced Materials(MOE),School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Shaanxi 710049,China)
基金
supported by the National Natural Science Foundation of China (52177151, 51631005 and 51907154)
the National Key Research and Development Plan of China (2017YFB0902503 and2016YFB0900802)
Beijing Science and Technology Plan(Z191100002019014)
the administration of Tsinghua University。
