Electric double layer

The electric double layer is a structure that forms at the interface between a liquid (like water) and a solid surface (such as a metal or mineral). When the surface contacts the liquid, it may gain or lose charge, causing ions in the liquid to arrange themselves near the surface to balance this charge. This creates two layers: one of charged particles on the surface, and another of oppositely charged ions in the liquid nearby. Together, these layers act like a very thin capacitor, affecting properties like electrochemical reactions, electrode performance, and colloidal stability.