A suggested new mechanism of charge decay of electrets and its application to their charge recovery

Abstract

A new mechanism of charge decay of electrets is proposed. In this mechanism the observed charge decay is only apparent and due to screening (not cancellation) of the electret charge at the atomic or microscopic level by electrical charges drawn from ions in the atmosphere or by electrical loading. The water film on the electret and the finite conductivity of the material constitute forms of electrical loading. The Cancellation of charge is avoided by the free charge being isolated in traps or the charge being due to exposed ends of aligned dipoles or both. It has been possible to evolve a process, essentially based on contacting each of the electret surfaces, one at a time, to a metal plate, to remove the screening charge and thus activate the (apparently) decayed electret, thus making life of the treated electrets almost infinite.