What is Nafion tubing used for?
What is Nafion tubing used for?
The Nafion® membrane tube removes water, alcohols, ammonia, amines, and other compounds having a hydroxyl group or potential for forming one under acid catalysis. Some compounds are not removed but are rendered by acid catalysis. Inorganic compounds are not normally removed, except water and ammonia.
How long does a Nafion membrane last?
Thicker membranes and fiber reinforced membranes are more appropriate for very high differential pressure applications (1000+ psi) or very long operating life (100,000+ hrs). Some of these factors can also be mitigated with good mechanical design of the electrolyzer cell, good catalyst configurations, etc.
How do you clean a Nafion membrane?
Nafion is often cleaned before testing by boiling in peroxide to remove organics, acid to ensure full conversion to proton form, and water to remove acid introduced in the prior step.
What is Nafion made of?
Developed at the DuPont Company, Nafion is a copolymer consisting of perfluorinated vinylether units and tetrafluoroethylene backbones. Depending on the equivalent weight of the polyelectrolyte, the ether side-chains carry sulfonic acid groups, which enable proton conduction.
What is Nafion dryer?
Gas Drying. Our dryers are powered by Nafion™ tubing, which selectively removes water vapor from a gas sample. This selectivity for water vapor allows our dryers to remove more moisture than other drying solutions, while maintaining analytes and water-soluble analytes in the gas sample.
How do you activate the Nafion membrane?
Based on those publication and previous studies, a specific acid treatment was performed in order to activate the membrane and increase the amount of water molecules per sulfonic group [5] Currently, sulfuric acid (H2SO4) with concentration below 1 M is used in standard method for the activation of Nafion [6].
How does a Nafion dryer work?
Nafion functions essentially as a highly selective, semi-permeable membrane to water vapor. If gases inside Nafion tubing are wetter than gases surrounding the tubing, drying will occur. If the surrounding gases are wetter, humidification will occur. In the simplest case, a strand of Nafion is suspended in ambient air.
When was Nafion invented?
1960s
What is Nafion™ Polymer. The Nafion™ polymer was invented by Walther Groth in late 1960s. Nafion™ is a copolymer of perfluoro-3,6-dioxa-4-methyl-7octene-sulfonic acid and tetrafluoroethylene (Teflon®). In simpler terms Nafion™ is a Teflon® backbone with occasional side chains of another fluorocarbon.
What is the burst pressure of Nafion tubing?
The burst pressure of Nafion™ tubing is generally greater than 200 psig (over 13 bar) but it varies with the diameter and wall thickness. An unusual property of Nafion™ is its propensity to change in physical size. As Nafion™ absorbs water, it swells by up to 22%.
How is the olefinated structure of Nafion obtained?
Nafion derivatives are first synthesized by the copolymerization of tetrafluoroethylene (TFE) (the monomer in Teflon) and a derivative of a perfluoro (alkyl vinyl ether) with sulfonyl acid fluoride. The latter reagent can be prepared by the pyrolysis of its respective oxide or carboxylic acid to give the olefinated structure.
What’s the burst pressure of a Nafion dryer?
When used as a dryer, it can operate up to 150°C. The burst pressure of Nafion™ tubing is generally greater than 200 psig (over 13 bar) but it varies with the diameter and wall thickness. An unusual property of Nafion™ is its propensity to change in physical size. As Nafion™ absorbs water, it swells by up to 22%.
How many molecules of water does Nafion absorb?
Nafion™ polymer very readily absorbs water, from the vapor phase or from the liquid phase. Each sulfonic acid group will absorb up to 13 molecules of water. The sulfonic acid groups form ionic channels through the bulk hydrophobic polymer, and water is very readily transported through these channels.