An Electrochemical Method for Testing the Scaling Susceptibility of Insulating Materials

Abstract

Calcium carbonate scale was precipitated from a hard water onto the surface of insulating material by a simple electrochemical technique, which consists of increasing the local pH by the electrochemical reduction of dissolved oxygen. When the polarizing electrode is a gauze metal wire, the surface density of nuclei is homogeneous, and the density of nucleation sites is well representative of the scaling susceptibility of the tested material. It is shown, for example, that the scaling susceptibility of polytetrafluoroethelyne is much lower than for other plastic materials. The crystal variety of the calcium carbonate nuclei is also correlated to the activity of nucleation sites. This original device can be used to perform comparative tests of all kinds of insulating materials, surface coatings, or surface treatments. © 2001 The Electrochemical Society. All rights reserved.