TRANSIENT BEHAVIORS OF INTERACTING ELECTRICAL DOUBLE-LAYERS

The unsteady-state potential and space charge distributions between tw o identical, planar parallel charged surfaces immersed in an a:b elect rolyte solution are examined theoretically. The effects of the ratio o f the diffusivities of counterions and colons, D-con/D-co, the mean di ffusivity (DconDco)(1/2), and the separation distance between two surf aces, H, on the transient distributions of electrical potential and sp ace charges are investigated. The result of numerical simulation revea ls that the extent of a system to reach its new equilibrium state depe nds largely on the magnitude of a scaled time v(=Dt kappa(2)). For a f ixed H, the greater the value of v, the closer a system to its new equ ilibrium state. For constant H and v, the smaller the ratio (D-con/D-c o), the greater the deviation of a system from its new equilibrium sta te. In addition, the effect of D-con on this deviation is greater than that of D-co.