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, the transport properties of a series of sulfonated poly(phenylene)s were found to strongly correlate to the ion exchange capacity of the polymer, and it was found that the transport in Nafion membranes was much higher than that in the sulfoneated polyphenylenes for a given ion exchange capability.
123 citations
TL;DR: In this article, composite humidity sensing films were made by using TiO2 nanowires, TEOS and Nafion, which were prepared by a dip-coating method.
Abstract: Homogeneous TiO2 nanowires were fabricated by hydrothermal method. SEM pictures proved the yield of nanowires to be more than 90%. Composite humidity sensing films were made by using TiO2 nanowires, TEOS and Nafion. FTIR absorption spectroscopy was used as a semi-quantitative method to get information about the protonation. The sensing films were prepared by a dip-coating method. The composite films coated on a pair of gold electrodes were tested for humidity sensors of resistance type. The measurement was carried out at five fixed humidity points in the range of 12–97% relative humidity, which were controlled by employing five different salt solutions. Resistance changes were about three orders of magnitude. The nanowires-based humidity sensors showed moderate sensitivity, short response and recovery time (<2 min) at relative humidity less than 76%, and good long-term stability.
123 citations
TL;DR: In this article, the morphology and swelling of PFSA ionomers (Nafion and 3M) as bulk membranes (>10 μm) and dispersion-cast thin films (<100 nm) are investigated to identify the roles of equivalent weight and side-chain length across lengthscales.
Abstract: Perfluorinated sulfonic acid (PFSA) ionomers are the most widely used solid electrolyte in electrochemical technologies due to their remarkable ionic conductivity with simultanous mechanical stability, imparted by their phase-separated morphology. In this work, the morphology and swelling of PFSA ionomers (Nafion and 3M) as bulk membranes (>10 μm) and dispersion-cast thin films (<100 nm) are investigated to identify the roles of equivalent weight (EW) and side-chain length across lengthscales. Humidity-dependent structural changes as well as different PFSA chemistries are explored in the thin-film regime, allowing for the development of thickness-EW phase diagrams. The ratio of macroscopic (thickness) to nanoscopic (domain spacing) swelling during hydration is found to be affine (1:1) in thin films, but increases as the thickness approaches bulk values, revealing the existence of a mesoscale organization governing the multiscale swelling in PFSAs. Ionomer chemistry, in particular EW, is found to play a key role in altering the confinement-driven structural changes, including thin-film anisotropy, with phase separation becoming weaker as the film thickness is reduced below 25 nm or as EW is increased. For the lower-EW 3M PFSA ionomers, confinement appears to induce even stronger phase separation accompanied by domain alignment parallel to the substrate.
123 citations
TL;DR: In this article, a dual-layer membrane is fabricated by laminating the Nafion 115 membrane with a highly orientated GO paper through transfer printing followed by hot-pressing.
123 citations
TL;DR: Preparation of hybrid organic-inorganic MCM-41 and SBA-15 silicas functionalized with perfluoroalkylsulfonic acid groups showed higher activity than commercial Nafion-silica composite for the esterification of long chain fatty acids with ethanol.
123 citations