Correlation of charge transfer in metal/polymer contact with contact potential

We report in this paper the magnitude of charge produced on some polymers by a non-frictional intermittent contact with a variety of metals. In order to eliminate charge leakage through ionisation of the atmosphere and sample contamination, we performed all our experiments in a vacuum environment with a pressure of about 10(-4)Torr. The contact potentials of the metal samples were measured relative to a gold reference electrode using a Kelvin vibrating capacitor. The contact charge exchange between metals and these polymers were measured using a proof-plane that was connected to the input of the electrometer. The result of the graph of charge measured versus the work function of the metal contactors was consistent with the theory. From the line fittings drawn in the graph of charge density versus metal work function of the metals, we calculated the contact potential for the polymers. Using these values and invoking a thermodynamic equilibrium model, we determined the thickness of penetration of the transferred charge into the polymers. The values we obtained are 620 nm for (Mg/PS) and 259 nm for (Pt/PMMA) and these we found to be comparable with the report of the previous researchers. (C) 2001 Elsevier Science B.V. All rights reserved.