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Showing 1 to 20 of 154 for “"nafion"”.
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Emission Capabilities of Nafion-Based Emitting Geometries
… pose as attractive options for this situation. Nafion, a fluorocarbon main-chain and sulfonic end groups composition, is the material used in the research presented in this work. Due to its extensive use in fuel cells, Nafion presents as a viable choice since numerous research has been performed …
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An investigation of nafion electrospray emitter tips
… The motivation for this work was to investigate Nafion, a perfluorinated sulfonic acid ionomer, as an alternative to the porous materials currently used for electrospray emitters. A common, repeatable method of manufacturing Nafion single emitter tips and arrays with different mixture ratios of …
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Thermal Analysis and Cation Doping of Nafion Membranes
… in</p> <p>perfluorosulfonic membranes such as Nafion. Hydration of the membrane is important</p> <p>for cell durability and longevity; low relative humidity accelerates membrane</p> <p>degradation. Cations can exchange with the proton on the sulfonate group in the polymer</p> <p>and modify …
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Electromechanical Transduction in Ionic Liquid-Swollen Nafion Membranes
… for ionomeric polymer transducers based on Nafion membranes. Ionic liquids are molten salts that are highly thermally stable and have an immeasureably low vapor pressure. Therefore, the ionic liquid-swollen transducers exhibit enhanced stability in their performance when operated for long …
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The “Apparent” Diffusion Coefficient of Electrons Through a Nafion Membrane
… as a probe molecule for diagnostic experiment of Nafion membrane integrity. Using hydrodynamic voltammetry with a rotating disk electrode (RDE), the signals between a bare electrode surface and one modified with a Nafion membrane can be differentiated to observe if there are any discrepancies in …
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Modified Nafion membranes for hydrogen production in Cu-Cl thermochemical cycle
… that utilizes a proton exchange membrane (PEM). Nafion, the most widely used PEM, is permeable to cations and neutral species. Because of this, Cu can permeate the membrane and enter the cathode where it is readily oxidized to metallic copper and deposited on Pt catalytic sites. This drastically …
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Constitutive model of aligned carbon nanotube/nafion nanocomposite ionic electroactive polymer actuators
… of these is lagging. In this work, A-CNT and Nafion PNC electrodes are manufactured and investigated as the key active element in ionic-electroactive polymer (i- EAP) devices. i-EAP actuators are known to create relatively large strains with low input voltages, and could therefore be used for …
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Chemiluminescence detection with a regenerable reagent by using tris(2,2'-bipyridyl)ruthenium(II) immobilized in nafion
… immobilized within a polymer (Nafion) coated on an electrode. Via control of the electrode potential creation of the reactive reagent Ru(bpy)$\sb3\sp{3+}$ is regulated. The Ru(bpy)$\sb3\sp{3+}$ reacts with analytes to yield chemiluminescence emission with the emission intensity …
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Ru,Rh,Ru Supramolecular Photocatalysts within Nafion® Membranes: Ion-exchange, Photoelectrolysis and Electron Transfer Processes
Perfluorosulfonate ionomers, such as Nafion® have been shown to demonstrate a profound affinity for large cationic complexes, and the study of polymer-bound cations may provide insight regarding Nafion® morphology by contrasting molecular size with existing models. The trimetallic complex, …
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Morphological and Mechanical Properties of Dispersion-Cast and Extruded Nafion Membranes Subjected to Thermal and Chemical Treatments
… properties of both extruded and dispersion-cast Nafion® membranes. The project can be divided into three primary objectives; obtaining a fundamental understanding of the glass transition temperature of Nafion®, determining the effect of thermal annealing treatments on the morphology and …
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Synthesis and characterization of purely sulphonated and composite membranes for high temperature fuel cells
… use, where the most accepted PEM used today is Nafion. Nafion is ideal due to its chemical durability and high proton conductivity however it is highly expensive and limited to 80˚C during operation. To target these issues two methods have been developed. One was to synthesize a new membrane …
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Morphological Characterization and Analysis of Ion-Containing Polymers Using Small Angle X-ray Scattering
… method in SAXS to study the morphology of Nafion 117CS containing different alkali metal ions in solid state. Contrast variation allows one to manipulate scattering data to obtain desired morphological information. At room temperature, only the crystalline peak was found for Na⁺-form …
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Comparative analysis of Polymer Electrolyte Membrane (PEM) fuel cells
… basic types, which are the Long-Side-Chain (LSC) Nafion® and the ShortSide-Chain (SSC) Aquivion® ionomer MEA with emphasis on performance and durability which are currently not well understood. In particular, electrochemical circuit models and semiempirical models were employed to enable …
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The Effects of Structure, Humidity and Aging on the Mechanical Properties of Polymeric Ionomers for Fuel Cell Applications
… humidity and aging on the mechanical behavior of Nafion® and Dais® ionomers. It was determined that the majority of the properties of these membranes were controlled by the formation and growth of the ionic clusters that were the direct result of the ionic nature of these materials. In the process …
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Gold Nanoshells: Synthesis and Applications to In Situ SERS
… for fuel cells. The interaction between Nafion and catalysts are of importance for the fuel cell development, but it has not been adequately addressed. Investigating the adsorption structure of Nafion at the Pt/electrolyte interface can lead to better understanding of the stability and …
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Transport and Structure in Fuel Cell Proton Exchange Membranes
… acid) copolymer membrane for fuel cells, Nafion, were compared. Species transport (protons, methanol, water) in hydrated membranes was found to correspond with the water-self diffusion coefficient as measured by pulsed field gradient nuclear magnetic resonance (PFG NMR), which was used as …
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Investigation of the Effect of Catalyst Layer Composition on the Performance of PEM Fuel Cells
… layer composition. The results show that both Nafion and carbon content significantly affect MEA performance. The physical characteristics of the catalyst layer including porosity, thickness, active platinum surface area, ohmic resistance, and apparent Nafion film thickness are investigated to …
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Polymer/nano-organic composite proton exchange membranes for direct methanol fuel cell application
… membrane 's cost and improve performance of Nafion membrane, three different kinds of membranes have been studied in this thesis. These membranes are SPEEK membranes, SPEEK/ZP composite membranes and Nafion/ZP composite membranes.
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Amperometric responses of some biosensor-related analytes at electrodes coated with semipermeable polymer layers: a comparative study /
… been studied at platinum electrodes coated with Nafion or electropolymerized polypyrrole and poly(o-phenylenediamine) and polyaniline (PANI) layers. Among the three layers studied, the Nafion layer shows superior properties. It possesses high permeability to hydrogen peroxide (95% as compared to …
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