Charge Transfer between a Single Polymer Particle and a Metal Plate due to Impact

Abstract

This paper describes an experimental investigation of the charge acquired by a single particle when striking a metal plate. The particle was projected from a pneumatic gun onto the metal plate. The initial charge carried on the particle before impact and the impact charge were measured under various conditions of impact velocity, v₀ (7-18m/s) and angle, θ (0°-60°).
The charge transfer is dependent not only upon the impact conditions but also upon the initial charge of the particle. The impact charge almost decreases proportionally to the increase in the initial charge. There is a particular value of this charge which results in no net transfer and which is independent of the impact conditions. This special point can be utilized to estimate the effective work function of insulating particles. While a larger impact velocity leads to a larger charge transfer because of the increase in the contact area, the data cannot be arranged with the maximum contact area derived from the normal component of the impact velocity, v₀cosθ. A much larger enhancement of the charge transfer is caused by the tangential component of the velocity, v₀sinθ. This fact is extremely different from the previous works (Refs. 2, 4) which describe that the tangential component had no effect on the charge transfer by collision.