Ion exchange membranes control ion transport, separation and efficiency in electrochemical systems. Our range includes cation exchange membranes, anion exchange membranes and bipolar membranes for applications such as flow batteries, water electrolysis, CO₂ electrolysis and electrodialysis.

Cation exchange membranes (CEMs) preferentially transport positively charged ions, such as H⁺, Na⁺ and K⁺, while restricting the passage of negatively charged ions. Depending on their chemistry and properties, they are used in proton exchange membrane (PEM) water electrolysis, fuel cells, flow batteries and electrodialysis.

Anion exchange membranes (AEMs) preferentially transport negatively charged ions, such as OH⁻, Cl⁻, HCO₃⁻ and SO₄²⁻, while restricting the passage of positively charged ions. Applications include alkaline and AEM water electrolysis, CO₂ electrolysis, flow batteries and electrodialysis.

Bipolar membranes (BPMs) combine a cation exchange layer and an anion exchange layer with an interface that promotes water dissociation. Under an applied voltage in the water-splitting direction, they generate H⁺ and OH⁻ ions and deliver them to opposite sides of the membrane. This enables acid and base production from salts, pH control and electrochemical processes requiring different pH conditions in adjacent compartments.

Membrane performance depends on the operating conditions. Different membranes have different chemical stability ranges: some are suited to acidic environments, others to neutral or strongly alkaline solutions. Transport properties, including ionic conductivity, resistance and selectivity, also depend on the operating pH, electrolyte composition and temperature. Chemical stability within a given pH range does not necessarily mean that transport performance remains constant across that range.

Ion selectivity also depends strongly on electrolyte ionic strength. In general, increasing ionic strength reduces the membrane’s ability to exclude oppositely charged ions, decreasing its permselectivity. Datasheet values therefore need to be considered alongside the conditions under which they were measured.

Technical datasheets are available through the individual product links. These provide membrane-specific properties, operating limits and measurement conditions to support selection for your application.

Need help choosing a membrane? Contact us to discuss your electrolyte, cell design and operating conditions.