Skip to main content
Aquivion® ion conducting polymers


Fuel Cells for Zero-Emission Transportation (powered by Hydrogen)


Aquivion® ionomers are used in proton exchange membrane fuel cells. Typical applications are anode or cathode binders and thin separator membranes (10-15μm). Aquivion® ionomers have a superior proton conductivity and water retention level at low relative humidity. This, combined with its high glass transition temperature, enables stack operation up to 120°C resulting in smaller front radiators and stacks.

Syensqo offers a broad portfolio of grades and product forms such as dispersion and powders. 


Key-value Proposition of Aquivion® Ionomer

  • Superior proton conductivity and water retention enable high power density even at low relative humidity and hence smaller stacks
  • High Tg enables stack operation up to ~120°C, allowing smaller front radiators

Recommended Product Forms:

Hydrogen Production via Water Electrolysis


Syensqo develops “best in class” membrane and nanodispersion grades for Membrane Electrode Assembly water electrolyzer applications.

As a key component of the polymer electrolyte membrane (PEM) water electrolysis cell, a polymer electrolyte membrane with good mechanical, thermal and chemical stability is required. Aquivion® ionomers widen the electrolyzer operating window; higher glass transition and higher levels of crystallinity improve thermal rating and mechanical stability, and reduce the gas crossover.

Furthermore, Aquivion® dispersions are applied as anode and cathode binders, thanks to the wide choice of proton conductivity grades and low catalyst deactivation.   


Key-value Proposition of Aquivion® Ionomer:

  • Good mechanical stability at 25% lower thickness leads to lower cell voltage and allows for lower system capex & opex 
  • High-temperature stability makes it possible to use Aquivion® at temperatures >85°C, reducing cell resistances and increasing system efficiency (less kWh per kg H2)
  • High chemical stability allows operating under temporary overload (e.g. for fluctuating RES production) and enlarges the electrolyzer operating window


Recommended Product Form: 

  • Dispersions of electrodes: Aquivion® D83-24B, D79-25BS
  • Membrane for PEM separator: Aquivion® E98-05S, E98-09S
  • Dispersion for membrane separator manufacturing: Aquivion® D98-25BS

Redox Flow Batteries (RFBs)

Aquivion® cation-conductive membranes are high-performing core components of redox flow batteries (RFBs).

The ongoing development path towards higher current density operation in RFBs makes Aquivion® membrane the proper fit with a variety of electrolyte configurations.


Key-value Proposition of Aquivion® Ionomer:

  • High cation conductivity not only for proton conduction under acid conditions (ph <0~7) but also for Na+/K+ ions under basic conditions (ph 7~14);  
  • High selectivity (low permeability) to prevent passage of the larger redox-active counter-ions crossover of which to the opposite electrolyte would be undesirable.
  • Unmatched chemical resistance also in extreme pH solutions for years of service life, 
    • be it at pH <0 (e.g. for Vanadium RFBs with acid concentration > 1 mole/l), 
    • or at ph ~14 (e.g. organic RFB at high state of charge, soc).

Combination of the above features allows developers to exploit the entire bandwidth between deep discharge (state-of-charge, SOC, ~5%) and full charge (SOC ~95%) without suffering RFB degradation or “memory effects”.  This technical advantage translates into a maximized kilowatt-hour capacity per amount of electrolyte.

Various RFBs leveraging different posolyte/negolyte combinations have already entered their commercialization stage; with Aquivion(R) identified as their best-performing membrane resin.


Key Benefits:

  • Smaller stacks thanks to unmatched conductivity and very high power density (kilowatt per SQM)
  • Lower opex thanks to better membrane selectivity reduces undesired crossover phenomena
  • Extended multi-year durability (e.g. in comparison with hydrocarbon-based membrane separator resins) reduces maintenance costs.
  • Access to a maximum of the specific electrolyte capacity (kilowatt-hour per kilogram, or per liter)

Recommended Product Forms: 

  • Membranes for RFBs separator: Aquivion® E87-05, E98-05, D98-25BS
  • Dispersions: Aquivion®, D79-25BS, D83-24B for casting of tailor-made types of separator membranes

Hydrophilization of PTFE-based Filtration Webs

Aquivion® is a two-phase, semi-crystalline fluoropolymer that has an affinity to both water and hydrophobic supports, such as PTFE. Therefore, its colloidal dispersion grades can be used as a surface treatment for hydrophobic substrates to improve their wetting behavior. The Aquivion® perfluorinated backbone will then orient towards and attach itself to the hydrophobic web surfaces, while its hydrated ionic moieties (-SO3H) placed on side chains create local hydrophilic domains on the outer and inner surfaces of the web.

Recommended Product Form: 

Acid Catalysis


The superacidity of Aquivion® sulfonic acid resin and its high concentration of functional groups enables this material to be used either alone (self-standing) or as an ingredient of composite structures that are active as heterogeneous catalysts. These encompass a wide range of organic syntheses and related reaction mechanisms already described in public literature.

Aquivion® opens another door to the circular economy as it constitutes a solid, reusable catalyst to substitute, for example, disposable liquid inorganic acids such as sulfuric acid or hydrofluoric acid.  Today, these acids still generate chemical waste requiring treatment prior to disposal or energy-intensive regeneration.


Key-value Proposition of Aquivion® Ionomer

  • Superacid 
  • Grades have acid capacities between 1.0 and 1.5 meq/g 
  • Resistant in highly aggressive environments (low pH, strong oxidants, strong reducing agents, etc.) 
  • Best-in-class thermo-mechanical stability up to 160 °C (320 °F) 
  • Adaptable to a variety of chemical reactions 
  • Adaptable to static or dynamic reactor designs 
  • Compatible with many organic solvents and water 
  • Safe and easy to handle 
  • Easy to recover from fluid phase 
  • Both ready-to-use powders and precursor grades for the manufacture of specific catalyst particles 
  • Zero leaching of chlorides, HCl or other trace chemicals 

Recommended Product Forms:

  • Dispersion: D79-25PS, D98