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SearchDr. Colleen Spiegel

Dr. Colleen Spiegel is a mathematical modeling and technical writing consultant (President of SEMSCIO) and Professor holding a Ph.D. and an MSc degree in Engineering. She has seventeen years of experience in engineering, statistics, data science, research & technical writing work for many companies as a consultant, employee, and independent business owner. She is the author of ‘Designing and Building Fuel Cells’ (McGraw-Hill, 2007) and ‘PEM Fuel Cell Modeling and Simulation Using MATLAB’ (Elsevier Science, 2008). She previously owned Clean Fuel Cell Energy, LLC, which was a fuel cell organization that served scientists, engineers, and professors world-wide.

There are numerous methods that have been developed for working with ion exchange materials. In this blog post, we will describe a few basic methods commonly used in ion exchange research to help a student or new scientist to work with these materials.


As we saw in the previous blog post, the process of ion exchange is influenced by a very large number of factors. The primary mode of ion transport is diffusion, which is process of the movement of atoms, ions, molecules, or energy from a region of high concentration to a region of low concentration.


Ion exchange materials are used to purify, separate, and extract many different types of molecules, including organic and biochemical molecules. When ion exchange materials involve these ion types, there may be additional complexities involved with the interaction.Some of the phenomena that may occur are:
- Secondary forces between the ionized group and counterion. These forces may consist of coordination, hydrogen, and van der Waals bonding.
- The pH can affect the percent ionization.
- The position of the functional groups can affect ion transport.
- Hydration of organic molecules can be more complex than inorganic ions.
- Organic ions may be larger than inorganic ions; thus, steric hinderances can reduce ionic interactions.
Therefore, ion exchange phenomena may be able to be explained chemically by stoichiometric reactions, but the actual ionic selectively may be determined by other interactions.





A numerical model was developed to predict the water concentration, temperature, potential and pressure across a Nafion membrane used in proton exchange membrane (PEM) based fuel cells. The numerical model consists of simultaneously calculating the diffusive flux for water and hydrogen, the proton potential and the pressure and temperature at each node...

Ion-exchanges membranes (IEMs) have many applications beyond fuel cells -- they can also be used to synthesize all types of compounds that are used in various industries. The most popular IEMs consist of polymeric resins with charged functional groups based upon their ion selectivity, they are referred to as anion-exchange (AEM) and...

Anion exchange membranes (AEMS) have been an active area of research for over a decade. AEMS can be used for fuel cells, redox flow batteries, electrolyzers, and even water desalination membranes. The electrolyte layer is the “heart” of electrochemical cells such as fuel cells, batteries, and because it transports ions from...

Alkaline fuel cells (AFCs) was one of the first extensively researched fuel cell types and was used by NASA for the Gemini, Apollo, and Space Shuttle missions. The first alkali electrolyte fuel cell was built by Francis Thomas Bacon (1904–1992) in 1939. He used potassium hydroxide for the electrolyte and...

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