Charge dynamic characteristics in corona-charged polytetrafluoroethylene film electrets
- 81 Downloads
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 wordsPolymer electrets Charge dynamics Material microstructure
Unable to display preview. Download preview PDF.
- Gerhard-Multhaupt, R., Künstler, W., Eberle, G., Eisenmenger, W., Yang, G., 1998. High Space-Charge Densities in the Bulk of Fluoropolymer Electrets Detected with Piezoelectrically Generated Pressure Steps.In: Space Charge in Solid Dielectrics. The Dielectrics Society, UK, p. 123–131.Google Scholar
- Hilczer, B., Malecki, J., 1986. Electrets. PWN-Polish Scientific Publisher, Amsterdam, p. 166.Google Scholar
- Sessler, G.M., Yang, G.M., 1996. Evolution of Charge Distributions in Polymers during Annealing. 9th Intern. Symp. electrets. Shanghai, China, p. 165–170.Google Scholar
- Xia, Z.F., Wedel, A., Danz, R., 1999. The Excellent Charge Storage Stability of Porous Polytetrafluoroethylene (PTFE) Film Electrets. 10th Intern. Symp. Electrets. IEEE Service Center, Piscataway, p. 23–26.Google Scholar