What is a Nafion tube?
Nafion tubing is a highly selective, semi-permeable membrane to water vapor. In normal use, a portion of Nafion tubing is used as a portion of the tube between a gas sample stream and a sensor. If the sample stream is much wetter than ambient air (such as breath samples), the sample falls to ambient humidity.
What is Nafion used for?
Nafion has found use in fuel cells, electrochemical devices, chlor-alkali production, metal-ion recovery, water electrolysis, plating, surface treatment of metals, batteries, sensors, Donnan dialysis cells, drug release, gas drying or humidifaction, and superacid catalysis for the production of fine chemicals.
How does a Nafion membrane work?
Nafion™ polymer functions as an ion exchange resin when exposed to solutions. The sulfonic acid groups form ionic channels through the bulk hydrophobic polymer, and water is very readily transported through these channels. Nafion™ polymer functions like a very selective, semi-permeable membrane to water vapor.
Is Nafion hydrophilic?
Nafion consists of hydrophilic sulfonic acid groups dispersed in a hydrophobic matrix of tetrafluoroethylene and perfluoroalkyl ethers [18,24,44–53]. The sulfonic acid groups sorb water swelling the hydrophilic network through which water and protons are transported.
How do you make a 5 Nafion solution?
Bottles marked 5% Nafion® 117 solution containing 15-20% water is available in the market in various capacities. Prepare a mixture containing 80-85 mL of ethyl alcohol and 20-15 mL of water.
Does Nafion dissolve in water?
The density of Nafion changes with sample history and solvent environment, and this can significantly impact the assessment of permeability measurements. From the data in Table 2, recast films are soluble in ethanol/ water mixtures, but even a minimal amount of heating imparts insolubility in ethanol/water.
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).
Is Nafion an ionomer?
Nafion®, a perfluorinated sulfonic acid ionomer, has been the standard DMFC (as well as hydrogen fuel cell) membrane.
What is a Nafion solution?
Fuel Cell Applications: Nafion™ solution (a diluted, liquid form of the same chemical used for a PEM fuel cell membrane) drastically reduces the amount of platinum needed as a catalyst by exposing a larger fraction of the platinum to the hydrogen gas.
How do you dilute Nafion?
Prepare a mixture containing 80-85 mL of ethyl alcohol and 20-15 mL of water. Keep on adding the above mixture solution in 5 wt% Nafion® 117 solution till the total volume of diluted Nafion® 117 solution becomes appxo. 20 times the original volume . It will be 0.25 wt% Nafion solution.
How do you dissolve Nafion pellets?
Nafion is sulfonated teflon (PTFE) which is practically insoluble in commonly used solvents. However, Perfluorocarbon Solvents can be used to dissolve nafion as per the attached article.
Is Nafion soluble in acetonitrile?
Density of films in acetonitrile is lower than that in water, consistent with the higher solubility of Nafion in organic solvents.