A method of determining the connectivity of ion-conducting hydrophilic channels within the Nafion polymer electrolyte membrane by way of pore-directed nanolithography has been developed. Electrochemical etching of a silicon surface is performed through a Nafion-membrane mask. The resulting silicon surface imaged by tapping-mode atomic force microscopy (TMAFM) provides a footprint of the hydroph...

To suppress methanol crossover in direct methanol fuel cells DMFCs , a Nafion-Bi2V0.75Sb0.25O5.4 composite membrane was prepared by recast method. Oxygen-ion conductive Bi2V0.75Sb0.25O5.4 powders were highly dispersed in a Nafion 117 membrane to physically block methanol crossover and/or chemically oxidize the methanol, which was confirmed by the difference in the methanol diffusion coefficient...

Exhibiting a very high surface area, good electrical conductivity and density of active sites, nitrogen-doped graphenic materials are considered as promising catalysts for the oxygen reduction reaction (ORR). Seldom studied in acidic media, N-doped foams were tested here cathode polymer electrolyte membrane fuel cell (PEMFC). The prepared via solvothermal-based process, by reacting either cyclo...

The aim of this study is to develop composite Nafion/GO membranes, varying GO loading, be used in a Unitized reversible fuel cell comparing its performance with the baseline Nafion. Water uptake, ion exchange capacity (IEC), tensile strength, and SEM (scanning electron microscope) analysis are discussed. revealed how homogeneously disposed into Nafion matrix. addition improves membrane strength...

Self-healing proton-exchange membranes (PEMs) made of poly(vinyl alcohol) (PVA) and Nafion were synthesized using the freeze-thaw method. Since PVA is more selective towards water than methanol, blend membrane successfully reduced methanol permeability improved selectivity compared to recast membrane. The addition also helped self-heal by promoting formation hydrogen bonds. In contrast pristine...

Sol–gel process was used for the preparation of Rhodamine 6G (R6G) doped silica xerogels, using tetraethylorthosilicate [TEOS, Si(OC2H5)4] as the precursor for the silica network. Silica alcosol was prepared by hydrolysis and polycondensation of ethanol (EtOH) diluted TEOS in the presence of citric acid (CTA) catalyst. The ethanolic R6G was added to the alcosol to trap R6G molecules inside the ...

─The Nafion/zeolite composite membranes were synthesized for polymer electrolyte fuel cells (PEMFCs) by adding zeolite in the matrix of Nafion polymer. Two kinds of zeolites, Analcime and Faujasite, were used. The physicochemical properties of the composite membranes such as water uptake, ion-exchange capacity, hydrogen permeability, and proton conductivity were determined. The fabricated compo...

Measurements of the mechanical and electrical properties of Nafion and Nafion/titania composite membranes in constrained environments are reported. The elastic and plastic deformation of Nafion-based materials decreases with both the temperature and water content. Nafion/titania composites have slightly higher elastic moduli. The composite membranes exhibit less strain hardening than Nafion. Co...

We present a method of fabricating Ge-doped SiO2 fibers with corrugations around their full circumference for a desired length in the longitudinal direction. The procedure comprises three steps: hydrogenation of Ge-doped SiO2 fibers to increase photosensitivity, recording of Bragg gratings with ultraviolet light to achieve modulation of refractive index, and chemical etching. Finite-length, rad...

Microbial fuel cells (MFC) are an emerging technology for wastewater treatment that utilizes the metabolism of microorganisms to generate electricity from organic matter present in water directly. The principle MFC is same as hydrogen cell and has three main components (i.e., anode, cathode, proton exchange membrane). membrane separates anode cathode chambers keeps anaerobic aerobic conditions ...