Charged chemical species are found in everyday life. Electrochemistry deals with charges in aqueous media. There are some well-known systems where the interfacial electrical charges are of common knowledge. The understanding of the charges at interfaces is of importance in many everyday phenomena: electrochemistry, microfluids, colloidal systems and solid—liquid interfaces. It has been found from experiments that the thickness of soap bubbles decreases as one adds electrolyte to the system. This arises from the fact that the magnitude of electrical double layer (EDL) decreases such that the charge—charge repulsion between the layers of soap decreases with added electrolyte. In many industrial applications the surface charge, for example, at the surface of glass or silica, is of much interest. Glass is one of the most commonly used materials in everyday life. The properties of glass are related to its surface characteristics.