Electrostatic surface potential decay on cellulose acetate

The decay of surface potential on cellulose acetate has been studied as a function of appropriate parameters. This material was chosen because of the relatively rapid nature of the decay process and the well-known interactions that occur between it and its environment. It was found that the rate of decay increases with charging voltage and, also, for thinner films. Surface potential profiles were also measured, as was the current flowing through the sample during both charging and discharging. Additionally, numerical simulations were also developed to explore the physics that underpin the above observations. These imply that it is field distortion by the charge deposited on the sample surface which results in the development, during charging, of a non-uniform equilibrium surface potential profile, not lateral charge migration. The subsequent decay process is then determined by the initial distribution that forms and a combination of surface and bulk phenomena; bulk phenomena dominate.