What is PFSA membrane?
The perfluorosulfonic acid (PFSA) membranes are characterized by high mechanical stability, excellent chemical inertness, good thermal stability, and high proton conductivity. These characteristics have made PFSA the material of choice for the automotive PEMFC for many years.
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What is a proton exchange membrane made of?
ionomers
A proton-exchange membrane, or polymer-electrolyte membrane (PEM), is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier, e.g. to oxygen and hydrogen gas.
What is perfluorosulfonic acid polymer?
Perfluorosulfonic acid polymers (PFSA) and perfluorocarboxylic acid polymers (PFCA) are typical fluorinated functional polymers that have been used to prepare ion exchange membranes, which serve as the barrier membrane to separate the anode and cathode com- partments of electrolytic cells in the production of alkali …
What is the meaning of PFAS?
The per-and polyfluoroalkyl substances (PFAS) are a group of chemicals used to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. Fluoropolymer coatings can be in a variety of products.
Is PFAS a polymer?
The class of per- and polyfluoroalkyl substances (PFAS) consists of polymers and nonpolymers.
How does a proton exchange membrane work?
Proton exchange membrane electrolyzers During operation water decomposes into oxygen and protons (hydronium ions, H+) at the anode, and protons migrate across the membrane to the cathode where they are reduced to hydrogen gas.
Is proton exchange membrane and polymer electrolyte membrane the same?
Proton-exchange membrane fuel cells (PEMFC), also known as polymer electrolyte membrane (PEM) fuel cells, are a type of fuel cell being developed mainly for transport applications, as well as for stationary fuel-cell applications and portable fuel-cell applications.
What is the chemical structure of PFAS?
Chemical Structure All PFAS contain a chain of carbon atoms bonded to fluorine atoms. Some also have a functional group at the end of the chain. These structures are the basis for different chemical properties and different chemical names.
What is Nafion made from?
Nafion comprises a polytetrafluoroethylene (PTFE) backbone with perfluorinated-vinyl-polyether side chains containing sulphonic acid end groups. When this material is hydrated, protons (H+ ions) become highly mobile, so that its proton conductivity can range up to 0.2 S/cm depending on the level of hydration (S = 1/ω).
What are characteristics of the chemical structures of PFAS and their properties?
Physical and Chemical Properties
| Property | PFOS (Free Acid) | PFOA (Free Acid) |
|---|---|---|
| Melting point (°C) | No data | 45 to 54 |
| Boiling point (°C) | 258 to 260 | 188 to 192 |
| Vapor pressure at 20° C (mm Hg) | 0.002 | 0.525 to 10 |
| Organic-carbon partition coefficient (log Koc) | 2.4 to 3.7 | 1.89 to 2.63 |
What are perfluorosulfonic acid ionomers?
Perfluorosulfonic acid ionomers, especially Nafion-based ones, are known since the late 1960s and have found wide application, especially in the chlor-alkali industry as membrane materials, besides in PEMs in FCs.
What is PFSA membrane made of?
Perfluorosulfonic acid (PFSA) polymers are the most commonly used materials for membranes for fuel cells. The PFSA consists of three regions: (1) a polytetrafluoroethylene (PTFE) backbone; (2) side chains of vinyl ethers (e.g., − O − CF 2 − CF − O − CF 2 − CF 2 −) which terminate in sulfonic acid groups in a cluster region (3) ( Fig. 10.5 ).
Can sulfonic acid functionalize non-fluorinated polyaromatics?
This has led to a vast number of novel sulfonic acid functionalized non-fluorinated polyaromatics1 and polymer materials comprising protogenic functions other than sulfonic acid (typically phosphonic and heterocycle functionalized materials).
What is the Sota of the Nafion 117/nafion 115 PFSA membranes?
The gray rectangle in the middle of the figure spots the state-of-the-art (SotA) when Nafion 117 or Nafion 115 PFSA membranes are used. The ε ΔH ≈ 70% at 1 A/cm 2 can be obtained using noble metal loadings of ca. 0.5 mg/cm 2 of Pt for the HER and ca. 2 mg/cm 2 of Ir (or IrO 2) for the OER.
