The present work proposes and demonstrates a methodology to capture the effect of operating conditions on ionic conductivity of membranes immersed in alkaline media. Based on reported experimental results for an anion exchange membrane (A-201 by Tokuyama) and a cation exchange membrane (Nafion 211), two novel expressions are developed for the ionic conductivity by incorporating the effects of s...

Reformate gas, a commonly employed fuel for polymer electrolyte membrane fuel cells (PEMFCs), contains carbon monoxide, which poisons Pt-containing anodes in such devices. A novel, low-cost mesoporous Si3N4 selective gas separation material was tested as a hydrogen clean-up membrane to remove CO from simulated feed gas to single-cell PEMFC, employing Nafion as the polymer electrolyte membrane. ...

The use of Cs0.5H0.5PW12O40 insoluble salt as a superacid promoter in the catalyst layer of a polymer electrolyte membrane fuel cell (PEMFC) has been investigated. An increase of performance has been recorded at intermediate temperatures (110–130 °C) and under low relative humidity (R.H.). The promoter appears to mitigate the ionomer dry-out effects in the catalytic layer and produces an increa...

We have used a combination of analytical theory and molecular-dynamics simulations to investigate the effect of various material parameters on the structure and proton conductivity of Nafion-like ionomer membranes. This has included the effects of varying the length of the molecular side chains and their spacing along the polymer backbone, as well as membrane stretching, membrane poling by the ...

The volume flow through a Nafion membrane originated by the simultaneous action of an electric potential difference and a pressure difference has been measured using aqueous KCl solutions under different experimental conditions. The behavior has been analyzed when both gradients act in the same and in the opposite sense. The results indicate that the simultaneous action of the pressure and pote...

Small-angle X-ray scattering (SAXS) and bulk volumetric measurements were performed on the perfluorinated ionomer membrane “Nafion”. The swelling experiments were conducted using controlled environments of different relative humidities. The membranes were oriented using uniaxial draw, both before and after conversion of the precursor material, as well as both sequential and simultaneous biaxial...

In this study different membranes were produced, aiming to evaluate their use in electrodialysis. These membranes were produced using conventional polymer (high-impact polystyrene) and polyaniline. The membrane characterization was done by FTIR spectroscopy, scanning electron microscopy (SEM), and thermogravimetry (TGA). The studies of the zinc and proton extraction ionic transport through the ...

Efficient recovery of ammonium, a valuable nutrient, from dilute streams is still an unsolved challenge. One possible approach to separate and simultaneously concentrate ammonium low concentration Donnan dialysis. To design process, mass transport model was utilized for both plate frame hollow fiber modules compared experiments. The chosen based on film theory, accounting resistances in the liq...