Chemical and electrochemical characterization of Nafion containing silver nanoparticles in a stripe-like distribution

Abstract

The particular chemical structure of Nafion with nanostructured and segregated hydrophilic and hydrophobic domains enables its use as a model structure for the manufacture of polymer-metal nanocomposites. Among such nanocomposites, samples of Nafion-117 containing Ag-NPs of ca. 10 nm prepared by Intermatrix Synthesis exhibited a particular distribution in the form of stripes, a regular pattern that could reveal the real morphology of the polymer. To evaluate the potential application of this engineered material (e.g. in electrochemical devices), these new nanocomposite membranes were characterized by different techniques: microscopic, surface chemical analysis, mechanical and electrical/electrochemical. X-Ray (XRD and XPS) analyses combined with synchrotron experiments (XANES) were used to determine the chemical speciation of Ag in the membrane. Membrane potential and impedance spectroscopy measurements showed that such Ag-NPs did not hinder the diffusive transport of protons in the membrane bulk, moreover, they slightly reduced the electrical resistance in fully hydrated state samples. The mechanical evaluation of the nanocomposite evidenced the reduction of the elastic character when compared with the unmodified Nafion-117 sample.

Preparation and Identification of Optimal Synthesis Conditions for a Novel Alkaline Anion-Exchange Membrane

“…The WU, IEC, and OH − conductivity of the prepared membranes in OH − form were shown in Table 2. As expected, the addition of Cu NPs decreased the WU of the CS:PVA membranes, as reported for Ag NPs in Nafion 117 [6]; in CS [14] IEC increased, with 5 wt % as the apparent optimum Cu NPs loading. This was attributed to the different oxidation states of Cu we shown above.…”

“…The Cu-exchange has been reported to decrease the tensile strength (TS) of Neosepta membranes from 2.67 ± 0.75 kg/m 2 to 2.26 ± 0.39 kg/m 2 [48]. Metal nanoparticles have not been observed to improve the TS performance of hydrophilic Nafion membranes either [6]. The results of 2–7 repetitions of the TS experiments performed for every CS:PVA membrane sample in this work are collected in Table 3.…”

“…AAEMs are generally designed to conduct anions preferentially and they are usually prepared from positively charged polyelectrolytes. The major challenges in the development of AAEMs are the improvement in their commonly low OH − conductivity and the required water management to maintain OH − transport from cathode to anode [2,3], whose regulation has been attempted by many procedures such as developing specific flow configurations [4], coating hydrophobic layers on hydrophilic AAEMs [5], ion-exchanging metallic ions in conductive polymers [6], and so on.…”

Rationally engineered nanosensors: A novel strategy for the detection of heavy metal ions in the environment

“…These Nafion®:Nafion® is typical sulfonated material generally used for proton exchange membranes (PEMs). Along with this, it is a public selected design for many other electrochemical applications and can upgrade the stability of the modified layer [150].…”

Electrocatalytic reduction of carbon dioxide on gold–copper bimetallic nanoparticles: Effects of surface composition on selectivity

“…The electrocatalyst slurry was prepared by dissolving 10 mg of each electrocatalyst with 1 mL mixture of isopropanol, absolute ethanol, ultra-pure water and an appropriate amount of Nafion solution [67] (5% Nafion, SIGMA ALDRICH), which is used as a binder to tightly deposit metal nanoparticles [68] and multi-walled carbon nanotubes on the carbon paper. After sonication and complete dissolution of the slurry, 72 μL of each composition was dispersed on 1 cm 2 carbon paper and dried at room temperature for 3-5 h.…”