Aquivion^® D83 PFSA Dispersions are based on the unique Short Side Chain (SSC) copolymer of Tetrafluoroethylene and a Sulfonyl Fluoride Vinyl Ether (SFVE) F2C=CF-O-CF2-CF2-SO2F of low molecular weight produced by Solvay Specialty Polymers. The ionomer dispersions contain its sulfonic acid form and are available in various solvent systems and concentrations.

Aquivion^® E79 and E87 ionomer membranes PFSA are melt-extruded products based on the unique Short Side Chain (SSC) copolymer of Tetrafluoroethylene and a Sulfonyl Fluoride Vinyl Ether (SFVE) F2C=CF-O-CF2CF2-SO2F of low Equivalent Weight (EW) produced by Solvay.

Though no particle maturation has been observed so far, stratification over ex­tended periods of time can not be fully excluded since dispersions are colloi­dal in nature. It is therefore recommended to shake the dispersion well before use. Ultrasound can be applied additionally if available.

After long storage periods additionally check the dispersion’s dry content on a small sample before use. Evaporation of organic solvents may have incurred increasing ionomer concentration or dispersion viscosity. If this is the case, add DI-water quantitatively to recover the initial con­centration.

Being superacids, Aquivion ^® PFSA ionomer dispersions constitute reactive systems. Solvay Specialty Polymers is not responsible of incorrect formulations.

Absence of air during hot-pressing phases can be of importance. It is favorable to decrease the temperature before e.g. opening the press. Reduction to around 120 °C (250 °F) is generally recommended. This may require 1 to 2 minutes of cooling time or be realized via active cooling. Membranes are delivered in acid form (>99,9 % SO₃H). A cleaning with H₂SO₄ or HNO₃ and H₂O₂ can be helpful but is not necessary in general.

Processing via CCM routes

When building MEA via catalyst-coated membrane (CCM) intermediates the application of Decal routes has evolved as state of the art. To combine the material in a way such that intense contact with low resistance is developed between membrane and catalyst layers, we recommend the following baseline parameters as a starting point for individual optimization of the transfer process:

for E87 series membranes

• Temperature 200 °C (390 °F)
• Press pressure between 1 and 5 MPa (150-700 psi)
• Hot-pressing times between 2 and 5 minutes
• Higher temperatures can require shorter hot-pressing times

for E79 series membranes

• Temperature 200 °C (390 °F)
• Press pressure between 1 and 5 MPa (150-700 psi)
• Hot-pressing times between 2 and 3 minutes
• Higher temperatures can require shorter hot-pressing times

Processing via GDE routes

If, however, internal customer processes foresee lamination of gas-diffusion electrodes (GDE) together with the ionomer membrane, slightly different parameters are preferable:

for E87 series membranes

• Temperature 150-160 °C (300-320 °F)
• Respect of pressure limitation by GDL/microporous layer
• Hot-pressing times between 0.5 and 2 minutes
• Higher temperatures can require shorter hot-pressing times

for E79 series membranes

• Temperature 150-160 °C (300-320 °F)
• Respect of pressure limitation by GDL/microporous layer
• Hot-pressing times between 1 and 2 minutes
• Higher temperatures can require shorter hot-pressing time

Proton Conductivity E79-3S

Proton Conductivity E87-05S

Mechanical Test in Machine Direction (ASTM D638)

Mechanical Test in Transverse Direction

The heart of the fuel cell is referred to as the stack. It is made from an array of individual cells, each separated by bipolar plates. The individual cell contains a crucial set of elements called the membrane electrode assembly (MEA). It is made from a polymeric proton exchange membrane (PEM) whose surfaces are coated on both sides with a catalyst.

Aquivion^® PFSAis an excellent choice for the PEM. Various grades are tailored for the type of PEFC to be produced or the processes applied during MEA production.