Journal of Zhejiang University-SCIENCE A

, Volume 5, Issue 8, pp 923–927 | Cite as

Charge dynamic characteristics in corona-charged polytetrafluoroethylene film electrets

  • Chen Gang-jin
  • Xiao Hui-ming
  • Zhu Chun-feng
Materials & Chemical Science


In this work, the charge dynamics characteristics of injection, transport and decay in porous and non-porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging, isothermal and thermal stimulating surface-potential decay measurements. The results showed that the initial surface potential, whether positively or negatively charging, is much higher in non-porous PTFE than in porous PTFE. For porous film the value of initial surface potentials increases with increase of film thickness. Higher charging temperature can remarkably improve charge stability. The charge dynamics are correlated to materials microstructure according to their scanning electron micrographs. For non-porous PTFE films, polarizability change of C-F bonds is the main origin of electret charges; but for porous PTFE film a large number of bulk and interface type traps are expected because of the greater area of interface and higher crystallinity.

Key words

Polymer electrets Charge dynamics Material microstructure 

Document code

CLC number



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Copyright information

© Zhejiang University Press 2004

Authors and Affiliations

  1. 1.Institute of Functional Material ResearchZhejiang University of Science and TechnologyHangzhouChina

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