Contact charging of silica glass particles in a single collision

Based on asymmetric contact, we present a contact charge model of high-energy trapped holes to predict the contact charging and explain the net charge transfer between identical silica glass surfaces in a single normal collision. Furthermore, the contact charging measurements are investigated on normal collisions of glassy particle-glassy particle-steel plane and glassy particle-glassy plane. The predicted results agree well with our experiments qualitatively and quantitatively: the impacting velocity and the particle size are two important factors affecting the magnitude of the contact charging.