What is Nafion®?

Perma Pure LLC manufactures components and devices primarily designed to dry and humidify gas streams. Our core technology is Nafion®, a Dupont co-polymer that is highly selective in the removal of water. We manufacture Nafion into tubing of various diameters to optimize the transfer of water through the Nafion. The water moves through the membrane wall and evaporates into the surrounding air or gas in a process called perevaporation. This process is driven by the humidity gradient between the inside and the outside of the tubing. In addition to drying and humidifying, our products can be used as ion exchange membranes and specialty separation membranes that take advantage of the unique properties of Nafion.

Nafion – The Perfect Drying and Humidifying Material

Nafion is a copolymer of tetrafluoroethylene (Teflon®) and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid. Like Teflon, Nafion is highly resistant to chemical attack, but the presence of its exposed sulfonic acid groups confers unusual properties. Sulfonic acid has a very high water-of-hydration, absorbing 13 molecules of water for every sulfonic acid group in the polymer; consequently, Nafion absorbs 22% by weight of water.

Unlike micro-porous membrane permeation, which transfers water through a relatively slow diffusion process, Nafion removes water by absorption as water-of-hydration. This absorption occurs as a First Order Kinetic reaction, so equilibrium is reached very quickly (typically with in milliseconds). Because this is a specific chemical reaction with water, gases being dried or processed are usually entirely unaffected.

Proven Technology

Perma Pure developed the first Nafion dryers more than thirty-five years ago. Today Perma Pure dryers are used throughout the world for gas sample conditioning prior to analysis by medical, scientific, and industrial instrumentation. This drying technology is branching out from the sampling environment into the process world, with applications ranging from medical drying to industrial process drying of various gases. Perma Pure humidifiers are also evolving from the analytical and laboratory arena to function as specialty humidifiers in applications ranging from medical gas humidification to humidifying hydrogen for fuel cells. In every application, Perma Pure products are guaranteed to perform reliably every time.