Observation of triboelectron emission from real copper surfaces in sliding contact with polytetrafluoroethylene and polyimide

We report the triboelectron emission (TriboEE) behaviors for copper surfaces in sliding contact with polytetrafluoroethylene and polyimide in relation to the XPS analysis. The TriboEE was measured using a gas-flow Geiger counter. The metal surfaces were subjected to the pretreatments of acetone cleaning, mechanical scratching and oxidizing. It was found that there is interdependence between the TriboEE intensity and the XPS elemental intensity. The formation of empty trapping sites on the polymer surface during the sliding process, which can accept the electrons transferred from the metal substrate, is shown to be a substantial process for the TriboEE to retain.

► Experimental set up for measuring triboelectron emission (TriboEE). ► Dependence of TriboEE yield from copper metal surfaces on PTFE and polyimide. ► Dependence of TriboEE yield on the preparation of real copper surfaces. ► Relationship of TriboEE yield to the XPS compositions of the metal samples. ► Relationship of TriboEE to the electron trapping site formed on the polymer surface.