Nondestructive determination of chloride concentration using Ag|AgCl electrodes produced by electrochemical anodization

Abstract

The stability of chloride ion selective electrodes in highly alkaline solutions is an important aspect when reliability and feasibility within reinforced concrete applications are concerned. The sensitivity of these electrodes largely depends on the properties of the AgCl layer, including uniformity, porosity, orientation, thickness, etc. These can be varied for optimum performance through adjusting the current density and anodizing time. In this study the Ag|AgCl electrodes were prepared in four different current density regimes and the resulting microstructural properties of the AgCl layer were correlated to potentiometric response in chloride-containing solutions, including synthetic concrete pore solution and cement extract. It was found out that lower level of the current density within the anodization process results later on in increased sensitivity and stability of the electrodes..