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	DuPont Fuel Cells \| Products and Services \| Nafion(r) Membranes and Dispersions
		For the past 30 years, DuPont™; Nafion® membranes and dispersions have been the product of choice for the fuel cell industry, providing unparalleled power output and durability.
		Today, Nafion® polymer has evolved into a leading-edge fuel cell material for a wide variety of applications.
		Advancements in durability and chemical stability mean that Nafion® membranes are more resistant to decomposition at higher temperatures than other membranes.
	www.dupont.com /fuelcells/products/nafion.html (167 words)

	Our Technology
		Nafion is not only highly resistant to chemical attack, it also exhibits highly selective absorption and transfer of compounds.
		In addition to the Nafion tubing, most Perma Pure dryers and humidifiers include a shell to contain the purge gas as well as fittings for gas connections to the gas stream and purge lines.
		When Nafion tubing bundles are used, the epoxy limits the maximum temperature to 120°C. The maximum internal pressure for all dryers is usually limited by the Nafion tubing to 80 psig at 20°C. Recent advances in some specialty dryers have increased this pressure tolerance.
	permapure.com /OurTechnology.htm (657 words)

	Spartanburg SC \| GoUpstate.com \| Spartanburg Herald-Journal (Site not responding. Last check: )
		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.
		Before the use of Nafion, industries used mercury containing sodium amalgam to separate sodium metal from cells or asbestos diaphragms to allow for transfer of sodium ions between half cells; both technologies were developed in the latter half of the 19th century.
		Nafion has been shown to be stable in cell cultures as well as the human body, and there is considerable research towards the production of higher sensitivity glucose sensors.
	www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=nafion (1401 words)

	Nafion - Wikipedia, the free encyclopedia
		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.
		Before the use of Nafion, industries used mercury amalgams to separate sodium metal from cells or asbestos diaphragms to allow for transfer of sodium ions between half cells; both technologies were developed in the latter half of the 19th century.
		Nafion has been shown to be stable in cell cultures as well as the human body, and there is considerable research towards the production of higher sensitivity glucose sensors.
	en.wikipedia.org /wiki/Nafion (1557 words)

	Method of forming robust metal, metal oxide, and metal alloy layers on ion-conductive polymer membranes - Patent 6673127
		A sample of Nafion 115 (8".times.8") was used as received except for wiping the surface clean with a soft tissue before placing on a drum.
		A first set of 6".times.6" samples of Nafion 115 was used as received from the manufacturer except for wiping the surface clean with a soft tissue and isopropyl alcohol before placing on a drum.
		A second set of 6".times.6" Nafion 115 samples was coated by the same procedure outlined above, except that the target for the high energy ionization beam was a pellet obtained by subjecting a powder of ruthenium dioxide to high pressure.
	www.freepatentsonline.com /6673127.html (6135 words)

	What is Nafion? (Site not responding. Last check: )
		Nafion belongs to the wide class of solid superacids catalysts, in that it exhibits acid stength greater than that of 100% H2SO4.
		It has hydrophobic (-CF2-CF2-) and hydrophilic (-SO3H) regions in its polimeric structure, and its supeacidity is attributed to the electron-withdrawing effect of the perfluorocarbon chain acting on the sulfonic acid group.
		Nafion is able to catalyze various reactions, such as alkylation, disproportionation, and esterification.
	www.personalweb.unito.it /gabriele.ricchiardi/Dati/ECCC-1/nafion.html (66 words)

	Nafion Acidity
		If Nafion were immersed in water, in theory, the pH of the water would remain unchanged.
		We reiterate that Nafion is not poisonous, does not cause any burns when in contact with the body, and in fact was in years past implanted into the human body as the tip of pacemaker electrodes inserted into the human heart in order to stabilize the rate of heartbeat.
		However, Nafion is extremely resistant to chemical attack (corrosion-resistant) and the sulfonic acid cannot be broken from the Nafion, even by very strong chemical reactions.
	www.permapure.com /TechNotes/Nafionacidity.htm (464 words)

	Molecular Modeling of Nanostructure and Water Transport in Nafion (Site not responding. Last check: )
		Hydrated Nafion membranes are used in fuel cell because of their high proton conductivity as well as dimensional and electrochemical stability.
		Nafion is a polyelectrolyte consisting of a rigid hydrophobic backbone and hydrophilic side chains with ionizable sulfonate end groups.
		Despite numerous studies on hydrated Nafion, the details of the structure and its influence on water and proton transport at the molecular level is not yet fully understood due to the limitation of experimental resolution to investigate the spatial nano-heterogeneity of the structure.
	flux.aps.org /meetings/YR03/MAR03/baps/abs/S810125.html (243 words)

	Selected Citation (Site not responding. Last check: )
		An investigation was undertaken to ascertain the fermentability of the hydrolyzates produced by a solid superacid, Nafion.
		Nafion was extremely efficient in hydrolyzing the oligomer content in the prehydrolyzates.
		The Nafion hydrolyzates were concentrated under partial vacuum to raise their xylose content to 4%.
	www.eere.energy.gov /cleancities/progs/afdc/vwbs2.cgi?1376 (204 words)

	USHIO LIGHT EDGE 24
		Nafion 117 film was exposed to low dose EB irradiation, at an accelerating voltage of 35 kV.
		Studies have shown Nafion, with its hydrophobic polyethylene backbone and pendant hydrophilic sulfonated side chains, to have a phase-segregated structure, providing a series of ion channels which facilitate permeation across the membrane.
		After considering the structure of Nafion with reference to our objectives, to prepare a material combining high conductivity with a low permeability to methanol, it was decided to proceed using a barrier strategy, Fig.1.
	www.ushio.co.jp /products/tech/le/le24/24_13.htm (2202 words)

	Mesoscale Simulations of Hydrated Nafion Membranes (Site not responding. Last check: )
		Nafion was presented as a branched sequence of beads.
		Because the size of the bead is relatively small, the skeleton needs some rigidity that was achieved by connecting atoms separated by 3 “normal” bonds by very weak bonds.
		Such a model cannot represent the conformations of long Nafion olygomers from atomistic simulation [1] because of the absence of long-range interactions in DPD.
	aiche.confex.com /aiche/2005/techprogram/P20950.HTM (458 words)

	Poster Abstracts- Second International Conference on Protein Stabilisation
		Nafion is commercially available as a solution in water-alcohol mixtures with a high (85-90%) content of organic solvent.
		The aim of the present investigation was the detailed study of the following basic factors, which affect both the stability and the activity of enzyme immobilised in Nafion membrane: the sequence of preparing of enzyme-polyelectrolyte complex in water-ethanol mixture, the alkaline used for Nafion neutralisation, the concentrations of all components in the enzyme-polyelectrolyte complex.
		The stability of GOD immobilised in the Nafion membrane was studied by repeated measurements of its activity.
	www.ejbiotechnology.info /feedback/proceedings/04/poster/p64.html (486 words)

	Pumps, Dryers, and Filters
		Water passes through the Nafion membrane and evaporates into the surrounding air until equilibrium with the external humidity is reached in a continuous process called perevaporation.
		Since Nafion is totally inert to the analyte gases, it is extremely selective; it removes only the water vapor, leaving the analyte gases otherwise unaffected.
		Nafion is not only highly resistant to chemical attack, it also exhibits highly selective absorption.
	www.enviro-analytical.com /gm/emissions/pumps.html (3192 words)

	Bristol SPM Group: Nafion Research (Site not responding. Last check: )
		Nafion is a commercially available perfluorosulphonate cation exchange membranes commonly used as a perm-selective separator in chloro-alkali electrolysers and as the electrolyte in solid polymer fuel cells.
		The membrane was therefore studied in different states of hydration obtained by placing the membrane and AFM in a specially constructed environmental chamber to control the humidity.
		Tapping mode phase imaging was successfully used to identify the hydrophobic and hydrophilic regions of Nafion.
	spm.phy.bris.ac.uk /research/nafion (256 words)

	New Hot Paper Comments by Joseph Wang and Yuehe Lin
		Nafion bears a polar side chain and hydrophobic backbone.
		The hydrohobic interaction is between the side-wall of CNTs and the backbone of Nafion, while the polar side-chain of the polymer leads to the solubilization of CNTs in polar solvents like aqueous buffer solutions.
		Using Nafion in a buffer solution, both enzyme molecules and carbon nanotubes can be dispersed in aqueous solutions, and the carbon nanotubes/Nafion/enzyme-mixed solution can be coated on an electrode surface to form a selective biosensor or biofuel cell.
	www.esi-topics.com /nhp/2004/july-04-YueheLin.html (676 words)

	New Hot Paper Comments by Joseph Wang and Yuehe Lin
		Nafion bears a polar side chain and hydrophobic backbone.
		The hydrohobic interaction is between the side-wall of CNTs and the backbone of Nafion, while the polar side-chain of the polymer leads to the solubilization of CNTs in polar solvents like aqueous buffer solutions.
		Using Nafion in a buffer solution, both enzyme molecules and carbon nanotubes can be dispersed in aqueous solutions, and the carbon nanotubes/Nafion/enzyme-mixed solution can be coated on an electrode surface to form a selective biosensor or biofuel cell.
	esi-topics.com /nhp/2004/july-04-YueheLin.html (676 words)

	Pumps, Dryers, and Filters
		Water passes through the Nafion membrane and evaporates into the surrounding air until equilibrium with the external humidity is reached in a continuous process called perevaporation.
		Since Nafion is totally inert to the analyte gases, it is extremely selective; it removes only the water vapor, leaving the analyte gases otherwise unaffected.
		Nafion is not only highly resistant to chemical attack, it also exhibits highly selective absorption.
	enviro-analytical.com /gm/emissions/pumps.html (3192 words)

	Ion Power - Products
		DuPont NAFION® PFSA NRE-211 and NRE-212 membranes are non-reinforced dispersion-cast films based on chemically stabilized perfluorosulfonic acid/PTFE copolymer in the acid (H+) form.
		NAFION® PFSA membranes are widely used for Proton Exchange Membrane (PEM) fuel cells and water electrolyzers.
		The membrane performs as a separator and solid electrolyte in a variety of electrochemical cells that require the membrane to selectively transport cations across the cell junction.
	www.ion-power.com /products.html (728 words)

	Anesthetic Gas Sampling Lines - Zefon International, Inc.
		The connector specification is not dependent on other accessories (Nafion ® tubing, filters) which may be included with the lines.
		The length is dependent on the distance from the point of attachment (anesthesia circuit) to the monitor.
		Nafion® dryer tubing has the unique property of removing moisture from the air sample which is passing through the gas line, without affecting the gas concentration.
	www.zefon.com /medical/gas.htm (404 words)

	Improved Performance of Hydrogen-Oxygen, Hydrogen-Air, Methanol-Air Fuel Cells Using Uracil and its Derivatives as ...
		Nafion also has the tendency to allow the flow of methanol from the anode to the cathode compartment, a phenomenon commonly referred as methanol crossover.
		In the APL fuel cell, the cathode is pre-treated with an organic molecule that allows oxygen reduction unimpeded, while preventing methanol from interfering.
		In other words, even if the Nafion membrane allows methanol to crossover to the cathode, the methanol does not affect the performance of the cathode, because the cathode pre-treated with our organic is protected against methanol.
	www.jhuapl.edu /ott/technologies/technology/articles/P01776.asp (449 words)

	STARs programme 2004
		Nafion, a perfluorinated ionomer polymer, is being used as a matrix for the dye.
		Therefore to prevent fluorescence quenching Nafion was used as it is permselective, meaning that it passes only cations and not anions.
		At the moment we are trying to modify the chemical structure of Nafion to improve the pH response of acridine in Nafion by moving the pKa back towards 7.
	www.nuigalway.ie /chem/AlanR/ARyderP14.htm (1564 words)

	Fuel Cell Today - DuPont Fuel Cells introduces new extended life membrane
		DuPont Fuel Cells announced last week the introduction of DuPont Nafion XL, a new extended life membrane that combines the advantages of mechanical reinforcement with enhanced chemical stability, enabling improved membrane durability.
		“Our latest innovation, the Nafion XL membrane, is a prime example because it enables a step change in membrane durability that approaches the automotive durability targets, moving us closer to making fuel cell vehicles a reality.
		In addition, DuPont Nafion XL demonstrates 30 times lower fluorine emission rates in open circuit voltage and lifetime improvement of greater than 25 percent in the load and relative humidity cycling test.
	www.fuelcelltoday.com /FuelCellToday/IndustryInformation/IndustryInformationExternal/NewsDisplayArticle/0,1602,8497,00.html (328 words)

	Mauritz - Nafion Research
		Its general chemical structure can be seen below in Figure 1, where X is either a sulfonic or carboxylic functional group and M is either a metal cation in the neutralized form or an H+ in the acid form.
		Moreover, the way in which the phase separated regions interact and act upon other substances is of great interest, not only in the scientific world, but in industry, as well.
		Because of this ionic morphology and the inherent ionomer properties of Nafion
	www.psrc.usm.edu /mauritz/nafion.html (889 words)

	Endeavors magazine, UNC-Chapel Hill: The Chemistry of Energy
		While Nafion membranes were first used in a fuel cell in the Gemini space program, they have been used commercially for the past twenty-five years in making chlorine bleach and other products, so much of their development has been geared to that application.
		Nafion doesn’t like very high temperatures, and it requires 100 percent relative humidity inside the fuel cell.
		To conduct, Nafion uses moisture to transport protons between sections of the membrane called acid groups.
	research.unc.edu /endeavors/fall2005/fuel_cells.php (2039 words)

	DupontFayettevilleWorksNafion (Site not responding. Last check: )
		The Nafion operation produces a variety of relatively uncommon monomer and polymers chemicals.
		The Nafion products are not common materials and tend to have a very high economic value.
		The primary air emissions from Nafion are acid fluorides and hydrogen fluoride.
	home.nc.rr.com /mckinneynara/DupontFayettevilleWorksNafion.html (419 words)

	Nafion-Mo2 (M= Zr, Si, Ti) Nanocomposite Membranes for Higher Temperature Operation of PEM Fuel Cells (Site not responding. Last check: )
		Nafion- MO2(M = Zr, Si, Ti) nanocomposite membranes were synthesized with the goal to increase the proton conductivity and water retention by the membrane at higher temperatures and lower relative humidities (120 oC, 40% RH) and also to improve the thermo-mechanical properties [1-2].
		The main obstacles to commercialization of PEM fuel cells are mostly related to the proton conducting materials, typically solid polymer electrolytes such as Nafion.
		The membranes synthesized by this approach were completely transparent and homogenous as compared to membranes prepared by the casting method which were cloudy due to the much larger particles.
	aiche.confex.com /aiche/2005/techprogram/P6823.HTM (492 words)

	Directory of open access journals
		Nafion membranes have been studied using dynamic mechanical analysis in the controlled force mode and clamp of tension film measurements for as received commercial Nafion membranes with different solvent contents and with different cations (Li+, Na+, K+, Rb+ and Cs+).
		In comparison with as-received Nafion membranes, the initial slope of the stress-strain curves decreases with increasing water contents in the Nafion membrane and also with the addition of methanol, ethanol and ethanol/water (50/50%, v/v) mixture.
		Nafion in salt form normally shows an increase in the initial slope from room temperature up to approximately 90ºC, after which the slope decreases with increasing temperatures.
	www.doaj.org /doaj?func=abstract&id=37045&recNo=8&toc=1 (170 words)

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