Ionomers

Ionomers are the ion-conducting glue of every membrane-electrode assembly — they bind catalyst particles to the support, wet the triple-phase boundary, and shuttle protons or hydroxides between the catalyst layer and the membrane. The chemistry you choose here decides whether your cell runs in acid or alkali, how it survives accelerated stress tests, and whether your CO2 electrolyzer suppresses parasitic hydrogen evolution.

This collection groups dispersions by ion-exchange family so you can match the ionomer to the catalyst layer and the membrane already in your stack.

Cation-exchange ionomers (PFSA, for acidic PEM systems)

• Long-side-chain PFSA (Nafion-type): the reference perfluorosulfonic acid ionomer for PEM fuel cells and PEM water electrolyzers. Used as the proton-conducting binder in catalyst inks and as a recast film. Equivalent weight and solvent system drive viscosity, dispersion stability, and final ionic conductivity.
• Short-side-chain PFSA (Aquivion-type): a perfluorinated sulfonic acid with a shorter pendant chain and higher glass-transition temperature, useful when the cell runs hotter or drier than long-side-chain chemistries tolerate.

Anion-exchange ionomers (AEI, for alkaline and CO2RR systems)

• Poly(aryl piperidinium) (PiperION-type): ether-free aromatic backbone with piperidinium cations; designed to resist the hydroxide-driven cleavage that degrades older AEM chemistries.
• Poly(phenylene) AEIs (Orion, NEXIONIC-type): all-carbon poly(phenylene) or quaternary-ammonium poly(phenylene terphenyl) backbones — a second route to ether-bond-free stability for AEMFC and AEM water electrolysis.
• Polyaromatic quaternary-ammonium (FAA-3-type): the long-standing aryl-ether-ketone benchmark in AEM research. Useful when you need to compare new materials against published baselines.
• Imidazolium-functionalized styrenic AEIs: available in hydrophilic grades for alkaline water electrolysis (keeping OER/HER catalyst sites wetted) and in hydrophobic grades tuned for CO2 electroreduction, where the imidazolium environment suppresses competing hydrogen evolution.

If you are building a PEM fuel cell or PEM electrolyzer, start with the cation-exchange (PFSA) options. If you are working on AEM fuel cells, alkaline water electrolysis, or CO2RR, start with the anion-exchange dispersions and pair them with the matching membrane. For the membrane sheets that complete the MEA, see Proton Exchange Membranes and Anion Exchange Membranes; for the catalyst-coated electrodes these inks are deposited on, see Electrolyzers and Fuel Cells.