Triboelectric charging of insulators – Mass transfer versus electrons/ions

In a recent publication on the mechanisms of triboelectric charging of insulators we interpreted our experimental results in terms of electron and ion transfer. We now report that these results can equally well be interpreted by the mass transfer mechanism. A process is proposed to distinguish between these. This would provide information relating to the idea that classification of triboelectric mechanisms of insulators may result from considering the amount of applied forces and frictional energy involved in the process, thus distinguishing between the mechanisms of non-frictional contact and pressing or rubbing contacts.