The Nafion™ polymer tubing helps increase accuracy during gas analysis. It is unique in its ability to seamlessly transfer moisture from one side of a membrane to the other side as a first order kinetic reaction. It is highly selective based on chemical reactivity and minimizes condensation damage to equipment.
Nafion™ Tubing Technology
Moisture control customized for your unique application.
How it Works
Unlike a porous membrane, Nafion™ Polymer selectivity is based on chemical reactivity, not the size of the molecule. The transfer of molecules from one side of the membrane to the other is done by a first order kinetic reaction. The Nafion™ polymer aims to attain equilibrium of the partial pressure of water vapor on the inside and the outside of its membrane. The driving force to transfer water molecules is the difference in humidity levels on either side of its membrane.
The Nafion™ polymer selectively transfers water vapors, leaving most analytes in the gas stream untouched.
The presence of the sulfonic acid adds three important properties to Nafion polymer:
1
Readily absorbs water in the vapor phase.
2
Functions as an acid catalyst due to the strong acid properties of the sulfonic acid group.
3
Functions as an ion exchange resin when exposed to solutions.
Chemical Properties of Nafion™ Polymer
Nafion™ polymer is a Teflon™ backbone with occasional side chains of another fluorocarbon. The side chain terminates in a sulfonic acid (-SO3H).
Apart from the sulfonic acid group, the Nafion™ polymer is a fluorocarbon. Like most fluoropolymers, it is extremely resistant to chemical attack (corrosion resistant). The sulfonic acid group is immobilized within the bulk fluorocarbon matrix and cannot be removed, but unlike the fluorocarbon matrix the sulfonic acid groups do participate in chemical reactions.
Nafion™ polymer physical properties are similar tothose of other fluoropolymers; it is a translucent plastic. When used as an ion exchange membrane, it operates at temperatures up to 190°C. When used as a dryer, it can operate at temperatures of 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™ polymer is its propensity to change in physical size. As Nafion™ polymer absorbs water, it swells by up to 22%. When exposed to alcohols it increases in size by up to 88%.
It’s highly selective nature makes the Nafion™ polymer ideal for analysis applications where moisture needsto be removed without analyte loss.
Nafion™ Polymer Permeability vs. Impermeability
Nafion is very effective at transporting only water while keeping the other gasses separated. For every 1,000,000 water molecules that pass through Nafion™ polymer, 1000 H2S or CO2 molecules or 1 O2 or N2 molecule would pass through Nafion polymer.
Permeability
Removed by Nafion™ Polymer
| Atmospheric Gases | H20 |
| Inorganics | NH3 |
| Organics | Alcohols, DMSO, THF |
Variable Losses
| Organics | Acids, Aldehydes, Amines, Ketones, Nitriles |
Impermeability
Totally Retained in Sample
| Atmospheric Gases | Ar, He, H2, N2, O2, O3 |
| Halogens | Br2, Cl2, F2, l2 |
| Hydrocarbons | Simple Forms (Alkanes) |
| Inorganic Acides | AHCL, HF, HNO3, H2SO4 |
| Other Organics | Aromatics, Esters, Ethers |
| Oxides | CO, CO2, SOX, NOX |
| Sulfur | COS, H2S, Mercaptans |
| Toxic Gases | COCL2, HCN, NOCl |
Drying Solutions
Perma Pure has decades of experience removing moisture to improve gas analysis accuracy.
Humidifying Solutions
When you need to effectively add just moisture to a therapeutic gas stream, our Nafion™ tubing is the perfect fit. Find out why Perma Pure is the perfect partner to co-develop your next humidification solutions. Functions as an ion exchange resin when exposed to solutions.
Custom Manufactured Assemblies
Build your unique assemblies with our experienced engineering, manufacturing, and regulatory teams resulting in cost andtime savings.