The Modern Understanding Of Glass Electrode Response

Electrochemcial experiments in combination with infrared spectroscopy and subsurface concentration profiling yielded information of ionic processes at the membrane surface of glass electrodes and resulted in a detailed mechanism of glass electrode response. This "dissociation mechanism" is based on phase boundary equilibria between anionic groups at the glass surface and hydrogen or alkali ions in the solution, which control the potential of the glass and the concentration of ions attached to the surface groups. The resulting concentration gradients between glass surface and bulk glass cause an interdiffusion of different ions, if they are not hindered sterically to penetrate into the glass, and a diffusion potential beneath the surface.