Scannlng electrochemical microscopy (SECM) in the feedback mode, where the steady-state faradaic current at a mlcrodlsk electrode tip Is measured as the tip Is scanned close to a surface, was used to lnvestlgate several dlfferent polymer films on electrode surfaces: poly( vlnylterrocene), N,N’-Ms[3-(t))prop~lE4,4‘-blp~ridkdun e r n e , and Naflon containing Os(bpy);+. The tip response (Le., pos...

The ability to accurately measure real-time pH fluctuations in-vivo could be highly advantageous. Early detection and potential prevention of bacteria colonization of surgical implants can be accomplished by monitoring associated acidosis. However, conventional glass membrane or ion-selective field-effect transistor (ISFET) pH sensing technologies both require a reference electrode which may su...

A Li-ion cell typically consists of a carbon-based negative electrode (NE); a porous polymer membrane separator (polypropylene and/or polyethylene); and a lithiated transition metal oxide (LiMxOy, M=Co, Ni, and/or Mn) positive electrode (PE). Electrodes are made by casting slurries of PE or NE-materials, PVDF-binder and carbon-black onto metal current collectors. Mixtures of Li-salts and organi...

Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion(®) were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate-PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigat...

A comprehensive study of the degradation of a highly active Fe/N/C catalyst in acid medium is reported. An accelerated aging protocol was applied in the temperature range of 20 to 80 °C. From fundamental rotating-disc electrode studies and polymer electrolyte membrane fuel cell investigations combined with identical-location electron microscopy and Mößbauer spectroscopy at various stages of deg...

We study the isothermal hydrogen adsorption and reaction at the E-TEK electrode of a polymer electrolyte fuel cell with a Nafion 117 membrane by impedance spectroscopy at 30 degrees C. We find that the impedance diagram must include a Gerischer phase element. Constant phase elements are not sufficient to describe the experimental data. This means that an adsorption reaction takes place in combi...

In this work, for the first time poly (benzoquinone) chromium (III) complex (PBQC) was synthesized with a one pot, one step, simple and fast method. This novel polymer was used for modification of graphite paste electrode for electrochemical determination of Mesalazine. Moreover, this novel modifier was characterized by Fourier transform infrared spectroscopy, Field emission scanning electron m...

We demonstrate targeted perturbation of neuronal activity with controlled release of neurochemicals from conducting polymer-coated microelectrodes. Polymer coating and chemical incorporation are achieved through individually addressable electrodeposition, a process that does not compromise the recording capabilities of the electrodes. Release is realized by the application of brief voltage puls...

An electrostatic-spray ionization (ESTASI) method has been used for mass spectrometry (MS) analysis of samples deposited in or on an insulating substrate. The ionization is induced by a capacitive coupling between an electrode and the sample. In practice, a metallic electrode is placed close to but not in direct contact with the sample. Upon application of a high voltage pulse to the electrode,...

The design of electrodes for polymer electrolyte membrane fuel cells (PEMFC) is a delicate balancing of transport media. Conductance of gas, electrons, and protons must be optimized to provide efficient transport to and from the electrochemical reactions. This is accomplished through careful consideration of the volume of conducting media required by each phase and the distribution of the respe...