Membrane Information

An Intro to Ion Exchange Material Laboratory Techniques

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.

Electrical Potential in Ion Exchange Processes
Conventional ion exchange processes use chemical reactants in solution for the ion exchange process. However, ion exchange processes are not just chemically driven, are also electrically driven. An example of an electrically driven ion exchange process is electrodialysis, (also known as electrodeionization), where ionizable species are removed from liquids using electrically active media and the electrical potential as a driving force for ion transport. Electrodeionization can also be used for water treatment, separation of electrolytes from non-electrolytes, concentrating or depletion of i..
Kinetics of Ion Exchange Materials Pt. 2

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.

Kinetics of Ion Exchange Materials
The rate of ion exchange depends on the rates of the chemical (ionic) reactions in the ionic exchange material (membranes, dispersions, beads, pellets, etc.), but it is often limited by the diffusion processes. The ion exchange process maybe primarily controlled by diffusion, which is dependent upon the material layers, structure, thickness and reactant rate of contact on the surface of the material. This blog post introduces the factors to consider when thinking about the kinetics of the ion exchange reactions. Mechanism of Ion Exchange Processes A common ion-exchange system is an ..
The Interaction of Organic and Biochemical Substances on Ion Exchange Materials

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:

  1. Secondary forces between the ionized group and counterion. These forces may consist of coordination, hydrogen, and van der Waals bonding.
  2. The pH can affect the percent ionization.
  3. The position of the functional groups can affect ion transport.
  4. Hydration of organic molecules can be more complex than inorganic ions.
  5. 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.

Membrane Comparison Chart

Membranes are essential for PEM fuel cells to operate. The Proton Exchange Membrane carries the hydrogen ions from the anode to the cathode without passing the electrons that were removed from the hydrogen atoms.

The Fuel Cell Store carries the largest selection of Membranes in the world! We help you compare all the Membranes we offer in one simple file so you can narrow down the perfect Membrane for your project. With our Membrane Comparison Table you can compare the specifications of all our Cation Exchange MembranesAnion Exchange Membranes, and Bipolar Membranes with ease.

How Ion Exchange Works
In nature, the majority of gases, liquids, and solids are not charged (in the neutral form). Ion exchange, where free ions are exchanged for different ions, occurs when there is an open network structure to carry the ions through it. There are many natural and man-made mediums that are ion exchangers, including solids, liquids, and gases. The medium needs to be in contact with the ion exchanger and these two entities exchange some of its ions for similarly charged ions. The medium is often a solid ion exchanger in contact with an aqueous solution or gas. If you recall from chemistry, there ..
An Introduction to Cation Exchange Membranes
Cation exchange membranes (CEMs) are frequently referred to as proton exchange membranes (PEMs) because they are often used in chemical reactions that generate protons. CEMs are used in various applications ranging from proton exchange membrane and microbial fuel cells to chlorine and caustic soda production. The cation exchange membrane (CEM) contains negatively charged functional groups (PO3-, COO–, and C6H4O–) in the membrane backbone, which allows cations to pass through. There are many types of CEM that have been used in the literature, including Nafion©, Fumatech, Aquiv..
Membrane Properties and Characterization for Zero-Gap CO2 Electrolyzers
Zero-gap electrolyzers are similar to fuel cells in design because the heart of the electrolyzer consists of two electrodes pressed against a membrane. These electrolyzers are called “zero-gap” because there is no gap between the cathodes, anodes, and the electrolyte. This design decreases the distance for ion transport because the layers are pressed or bonded together. The zero-gap CO2 electrolyzers can achieve high current densities (≥100 mA/cm2) by delivering gaseous CO2 to the cathode. The efficiency of these electrolyzers depends upon the catalysts used, the operating conditions, and o..
Compact Transient Model for Nafion Membranes

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...