The Casimir interaction in a nonlocal electrolyte slab

In this paper, the Casimir force per unit area across a nonlocal slab of an electrolyte between two semispaces of ordinary materials has been studied through the scattering approach. Because of the insufficiency of Maxwell's boundary conditions, additional boundary conditions are used as well. The numerical calculations show that for polystyrene semispaces at small separations, ascending the concentration causes intensifying the Casimir pressure. However, it is illustrated that in the case of silver substrates the Casimir pressure has the same amount for two electrolyte concentrations and this intensification does not occur by increasing the concentration. At small separations for polystyrene semispaces, the Hamaker coefficient has two different magnitudes corresponding to 90 and 0.9 mM concentrations, but for silver substrates the Hamaker coefficient starts from the same value for both concentrations.