PalmSens Knowledge Base
This knowledgebase contains all you need to understand potentiostats, electrodes and how to use them to perform for example coating research or analyze paint. It will give an intro...
This chapter deals with Electrogravimetry and the Electrochemical Series. Deposition of metals can also be used for analytical methods. The differences in the standard potentials allow individual precipitation of different metals in the same solution.
This chapter explains corrosion and methods to prevent it. Corrosion is an important research field due to the fact that corrosion causes big amounts of damage to machines and monuments. Understanding and preventing corrosion is the goal of corrosion research.
This series of articles and corresponding experiment aims to provide an introduction to electrochemical experiments. This series in particular is meant to facilitate a transition from what is taught in most schools and the slightly more advanced level of potentiostatic experiments.
In this section it is explained why Electrochemical Impedance Spectroscopy (EIS) is a suitable technique to perform research on coatings meant for food storage. Furthermore, it will be explain how to estimate the time until an unacceptable resistance of the coating is reached based on EIS measurements. During the calculations also the order of the reaction leading to the failing of the coating and the reaction rate will be determined.
In this section the reasons for choosing a certain DC potential is explained. The advantages of using Ecorr as a reference point will be presented as well as how to choose in PSTrace to use potentials versus the reference electrode or versus Ecorr.
In this section of the handbook the Warburg Impedance and the Constant Phase Element (CPE) are introduced, which represent electrochemical effects with no corresponding real electronic components. Furthermore, some equivalent circuits for typical corrosion systems are presented.
In this chapter the two main ways of visualizing Electrochemical Impedance Spectra (EIS), the Nyquist and Bode plot, are presented and it is explained how different EIS of easy electronic circuits will be plotted in the Bode and Nyquist plot. This demonstrates the advantages and disadvantages of the two plots as well as serving as a foundation to understand the analysis of EIS by utilizing equivalent circuits.
To understand the foundation of corrosion current measurements the Tafel plot and the Evan’s diagram are explained. The connection between a polarization curve and the Evan’s diagram is explained and how to extract the corrosion current from a polarization curve.
Here are some general comments on trouble shooting that are valid for any experiment. We made this list to enable even not very experienced users to find the sources of trouble as soon as possible to keep the frustration level for you and coworkers as low as possible.
In this extensive section Polarization Curves are discussed. How to setup your equipment, the choice of parameters as well as the data processing is discussed. This will enable you to record a polarization curve and extract the corrosion rate from it by using PSTrace 5. Furthermore, the polarization curves and Evan’s diagrams for passivation films (thick and thin) are discussed. This section closes with a brief description of crevice and pitting corrosion.