Charge storage and its dynamics in positively corona charged polytetrafluoroethylene film electrets

Abstract

In this paper, charge storage and its dynamics in positively corona char ged polytetrafluoroethylene（PTFE） film electrets have been studied. It is foun d that from room temperature to 100℃ and from about 150℃, especially from 180 ℃ to higher temperatures, slow retrapping controls the transport of detrapped c h arge; however, from about 100℃ to 150℃ the fast retrapping plays a dominant ro le. The increase of the initial surface potential will lead to a significant decay of charge density, so by means of properly controlling the charging parameter an d the heat treatment process we can get positively and negatively charged PTFE f ilm electrets with the same charge density, which not only have a similar charge storage life but also an outstanding charge storage stability. 