Topic
Nafion
About: Nafion is a research topic. Over the lifetime, 9110 publications have been published within this topic receiving 320865 citations.
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TL;DR: In this paper, ex situ aging tests were performed on Nafion® 112 in practical fuel cell usage conditions, which revealed membrane degradation through a modification of sulfonic acid end-groups.
106 citations
TL;DR: In this paper, the electrical conductivity and proton and fluorine-19 NMR spin-lattice relaxation times (T1) in acid form NAFION 105, 117, and 120 conditioned at various levels of relative humidity have been carried out.
Abstract: Measurements of the electrical conductivity and proton and fluorine-19 NMR spin−lattice relaxation times (T1) in acid form NAFION 105, 117, and 120 conditioned at various levels of relative humidity have been carried out. Complex impedance studies were made along the plane of the polymer film at frequencies from 10 to 108 Hz at room temperature and pressures up to 0.3 GPa. The NMR measurements were made at room temperature and pressures up to 0.25 GPa. Both types of measurement were also carried out on various concentrations of sulfuric acid in water. The electrical conductivity decreases with increasing pressure for low water content acid solutions and low water content NAFION samples. This behavior (positive activation volumes) is that expected for “normal” liquids and for ions in polymers where the motion of the ions is determined by the host matrix. However, for high water contents, the reverse is true. The electrical conductivity increases with increasing pressure which gives rise to a negative activ...
106 citations
TL;DR: In this paper, a porphyrin-based NO sensor has been prepared using Mn(II)-meso-tetracarboxyphenylporphyrin linked via a spacer chain to a pyrrole unit.
106 citations
TL;DR: Hybrid membranes (SPEEK/g-C 3 N 4 ) composed of sulfonated poly(ether ether ketone) and graphitic carbon nitride (gC 3N 4 ) are fabricated via a solution-casting method for vanadium redox flow battery (VRB).
106 citations
TL;DR: In this paper, a thin barrier layer is plasma polymerized on Nafion 117 membranes to reduce the methanol permeability to acid base and covalently crosslinked blend membranes.
Abstract: The permeability of Nafion® 117 and some types of acid-base and covalently crosslinked blend membranes to methanol was investigated. The methanol crossover was measured as a function of time using a gas chromatograph with a flame ionization detector. In comparison to Nafion, the investigated acid-base and covalently crosslinked blend membranes show a significant lower permeation rate to methanol. Additionally, another method to reduce the methanol permeability is presented. In this concept a thin barrier layer is plasma polymerized on Nafion 117 membranes. It is shown that a plasma polymer layer with a thickness of 0.3 μm reduces the permeability to methanol by an order of magnitude.
106 citations