Effects of Externally Applied Electric Field on the Electric Double Layer Formed in an Electrolyte Layer and its Contribution Towards Joule Heating

Joule heating of liquid films in the presence of an externally applied electric field is influenced by the formation of the electric double layer. The thickness and charge distribution inside the electric double layer determine the extent of interaction of the charge in the electric double layer with the externally applied electric field and the Joule heating of the electrolyte layer. For this reason, the effects of externally applied electric field (both parallel and along the normal to the surface) on the electric double layer are being studied in the present paper. In the absence of the externally applied electric field, the distribution of the electric potential in the double layer is given by Poisson equation. Assuming Boltzmann distribution for the ionic concentration in the double layer, one arrives at Poisson-Boltzmann equation for the electric potential distribution. The externally applied electric field changes this electric potential distribution. Hence, the contribution of the externally applied electric field is studied by including it in the Poisson-Boltzmann equation.