Carbon aerogels and Cr-, Fe-, Co-, and Ni-containing carbon aerogels were obtained by pyrolysis, at temperatures between 500 and 1800 °C, of the corresponding aerogels prepared by the sol−gel metho...

Catalytic graphitization of carbon aerogels by transition metals

Realisation de la resolution spatiale des profils de concentration dans le domaine du micrometre et controle des phenomenes se produisant dans un domaine temporel de l'ordre de la milliseconde

Measurements within the diffusion layer using a microelectrode probe

Coordination chemistry in two dimensions: chemically modified electrodes

Quantitative analysis of reversible diffusion-controlled currents of redox soluble species at interdigitated array electrodes under steady-state conditions

Le traitement thermique d'une electrode de carbone vitreux, a 725°C sous vide pousse (<2.10 −6 Torr) permet d'obtenir une electrode active vis-a-vis de l'oxydoreduction du ferro-ferricyanure et pour l'oxydation d'acide ascorbique

Vacuum heat-treatment for activation of glassy carbon electrodes

The optimum composition of a compression-molded Kel-F-graphite composite electrode is investigated for the electrochemical (EC) detection of effluents, including phenollic compounds, separated by reversed-phase high-performance liquid chromatography (HPLC). Optimum compositions of 10 to 15% graphite by weight can be rationalized on the basis of the particulate structure of the graphite active sites. The electrode is compatible with a wide range of organic solvents and its linear response to the target compounds extends over 5 orders of magnitude in concentration. The detector has been applied for the determination of a range of phenolic species in natural water and a coal gasifier waste water sample. Detection limits for a variety of phenols range from 3 to 15 pg. Repetitive injections yield peak heights with RSDs typically less than 1%. The long-term stability of the electrode is also demonstrated.

Kel-F-graphite composite electrode as an electrochemical detector for liquid chromatography and application to phenolic compounds

Chronoamperometric response at carbon-based composite electrodes

Evidence for the presence of a thin carbon-particle layer on polished glassy carbon electrodes

Results obtained in this laboratory and elsewhere suggest that carbon composite electrodes may possess a signal-to-noise (S/N) advantage compared to continuous electrodes such as glassy carbon when used for detection of analytes in flowing streams. One succomposite electrode which appears partic- ularly attractive in this regard is the Kel-F-graphite (Kelgraf) electrode, compression molded from Kel-F and powdered graphite and containing 5 to 30% graphite by weight. Studies of the electrode surface by scanning electron microscopy and X-ray photoelectron spectroscopy in conjunction with electrochemical investigations employing chronoamperometry, cyclic voltammetry, and capacitance measurements have led us to view the electrode surface as an ensemble of rnicroelectrodes, the dimensions of which can be varied by changes in particle size and/or ratio of Kel-F to graphite in the composite. The S/N advantage of the composite electrode apparently arises from a signal (current) enhanced by radial diffusio...

Duane E. Weisshaar

Papers

Kel-F-graphite composite electrode as an electrochemical detector for liquid chromatography and application to phenolic compounds

Chronoamperometric response at carbon-based composite electrodes

Evidence for the presence of a thin carbon-particle layer on polished glassy carbon electrodes

Carbon Composite Electrodes for Liquid Chromatography/Electrochemistry: Optimizing Detector Performance by Tailoring the Electrode Composition

Evaluation of kel-f—graphite electrodes as detectors for continuous flow systems