University of Iowa Research Foundation

Other

Leddy, Johna

Johna Leddy

Sudath Amarasinghe

Lois Anne Zook

Shelley D Minteer

Wayne L Gellett

Krysti L Knoche

Luke M Haverhals

Drew C Dunwoody

Flavio Tinoco

Pengcheng Zou

William Joseph Leddy, Iii

Joseph Tesene

Jacob Lyon

Catherine Spolar

Hachull Chung

Nadeesha P W Rathuwadu

Angela Wolf

Timothy Michael Paschkewitz

Murat Ünlü

Chester G Duda

Chaminda Hettige

Electrochemically reacting a lanthanide or actinide in solvent at a working electrode; wherein the solvent comprises an organic solvent such as acetonitrile which have a dielectric constant of at least three; wherein the solvent system further comprises an electrolyte; wherein the working electrode comprises an ionically conducting or permeable film such as a fluorosulfonate film; wherein at least one ligand such as triflate distinct from the ionically conducting or permeable film is present; wherein the ligand is chemically similar to a structure in the ionically conducting or ionically permeable film; and optionally wherein the electrochemical oxidation or reduction is carried out under the influence of a magnetic field which favorably enhances the reaction. Improved electrochemical methods, identification, and separation can be achieved. Also, an electrochemical device, wherein the device is adapted to employ the oxygen reduction reaction (ORR) at the cathode, wherein the cathode is magnetically modified, or the electrolyte comprises at least one lanthanide or actinide, or both.

Lanthanide electrochemistry

Electrochemically reacting C-1 compounds including carbon dioxide, formic acid, formaldehyde, methanol, carbon monoxide in the presence of at least one lanthanide and/or at least one actinide. Reducing carbon dioxide or reacting C-1 compounds such as HCOOH (formic acid), HCHO (formaldehyde), CHOH (methanol), or CO (carbon monoxide) with use of an electrochemical device, wherein the device comprises at least one cathode, and at least one anode, and at least one electrolyte between the cathode and the anode, wherein the electrolyte comprises at least one lanthanide and/or actinide compound. The electrode can be modified with a film such as an ionically conducting or ionically permeable film, optionally comprising a magnetic material. Polar organic solvent such as acetonitrile can be used. Electrocatalysis and/or reaction mediation is observed. Devices can be adapted to carry out the methods. The device can be part of a fuel cell, a battery, an electrolyzer, or an electrosynthetic device.

Carbon dioxide reduction and carbon compound electrochemistry in the presence of lanthanides

A device which can increase the rates of interfacial reactions including heterogeneous electron transfer reactions, the device comprising at least one sono(electro)chemical cell adapted to hold a thin layer of condensed fluid which is optionally adapted to participate in a heterogeneous electron transfer reaction, wherein the cell is further adapted to provide an ultrasonic transducer face to propagate sound waves into the thin layer of condensed fluid, and wherein the cell is still further adapted with an opening to provide the thin layer of condensed fluid with at least one interface which provides for reflection of the sound waves from the interface back into the thin layer of condensed fluid. The cells are configured to provide for a thin layer operation as opposed to a bulk operation. In method embodiments, ultrasound is applied to the thin layer of condensed fluid. The application of ultrasound is carried out both without cooling of the cell and without pressurization of the cell. Methods of using the device include fuel cells and fuel cell electrodes. Systems having anodes and cathodes are also provided.

Thin layer sonochemistry and sonoelectrochemistry devices and methods

Lanthanide Electrochemistry

A device comprising at least one electrode and at least one cell such ascyanobacteria disposed on said electrode for producing ammonia. A layer of polymer, such as ion exchange polymer, can be used to help immobilize the cells. Whole cells or partially disrupted cells can be used. A method and a system for producing ammonia, comprising contacting at least one cyanobacteria such ascyanobacteria with a media with an electrochemical perturbation is disclosed. The potential enhances ammonia production.

Ammonia production using bioelectrocatalytical devices

Battery electrodes with desirable discharge performance comprise manganese oxide and magnetic particles. Corresponding power cells have improved specific discharge capacities. Furthermore, magnetically modified manganese dioxide electrodes are found to have significantly improved cycling properties that suggest the possibility for improved performance in secondary batteries.

Batteries and battery components with magnetically modified manganese dioxide

Disclosed are self-hydrating membrane electrode assemblies (MEAs), including MEAs that have been magnetically modified, which comprises (i) a cathode comprising an electrically conducting material having a catalytic material on at least a portion of a first surface thereof, the catalytic material comprising an effective amount of at least one catalyst component and at least one ion conducting material; (ii) a separator adjacent to and in substantial contact with the first surface of the cathode and comprising an ion conducting material; and (iii) an anode adjacent to and in substantial contact with the surface of the separator opposite the cathode and comprising an electrically conducting material having a catalytic material on at least a portion of a surface thereof adjacent to the separator, the catalytic material comprising an effective amount of at least one catalyst component and at least one ion conducting material; wherein the separator permits water to pass from the first surface of the cathode to the surface of the anode in an amount sufficient to sustain hydration of the anode and further wherein the cathode produces sufficient water to sustain hydration of the anode. Also disclosed are methods of manufacture of the self-hydrating MEAs, as well as fuel cells that require only a self-hydrating MEA and a source of fuel.

Self-hydrating membrane electrode assemblies for fuel cells

Amounts of volatile organic compositions can be evaluated from vapor samples based on the time dependent response of a fuel cell contacted with the vapor sample at its anode. The time response of the fuel cell signal, e.g., voltage or current, is de-convoluted using a set of standard curves for an equivalent fuel cell configuration obtained separately for each of the volatile organic compositions of a fuel cell with an equivalent construction as the sample-evaluation fuel cell. The methodology can be implemented on a system with an appropriate vapor collection device suitable for the particular application. The method and system can be used to analyze breath samples to evaluate ethanol levels or other volatile organic composition. The system can be a breathalyzer, a vehicle interlock, a medical analysis device or a sensor of environmental or industrial interest.

Multicomponent analysis of volatile organic compositions in vapor samples

A method of diagnosing the health of an individual by collecting a breath sample from the individual and measuring the amount of each of a plurality of analytes in the sample. The amount of each analytes is measured by fitting a time response curve of a sample-evaluation fuel cell in which the fuel cell sample electrode is contacted with the sample with the analysis based on a function of standard time response curves for an equivalent fuel cell configuration obtained separately for each of the analytes on a fuel cell with equivalent construction as sample-evaluation fuel cell. Each of the plurality of analytes is generally indicative of an aspect of the individual's health. Suitable analytes include, for example, inorganic compounds as well as compositions that exhibit negative reduction reactions at least for a portion of the time response curve. In particular, acetone exhibits a negative potential/current peak when it is an analyte in a fuel cell in an sample electrode with a counter electrode exposed to oxygen, which may or may not be introduced in the form of air. Various forms of analysis to estimate acetone concentrations in the breath can be used.

Breath-based sensors for non-invasive molecular detection

An electrically conducting electrode having a composite and a current collector in electrical contact with the composite, the composite can comprise at least about 10 weight percent electrically conductive particles, at least about 0.5 weight percent magnetic particles, and an optional polymeric binder, wherein composite is at least about 80 weight percent with respect to the combined weight of the electrically conductive particles, the magnetic particles and the binder. Electrochemical systems can effectively use these electrodes to improve system performance.

Magnet incorporated electrically conductive electrodes

The present invention is directed to methods for making magnetically modified electrodes and electrodes made according to the method. Such electrode are useful as electrodes in batteries, such as Ni-MH batteries, Ni&#x2014;Cd batteries, Ni&#x2014;Zn batteries and Ni&#x2014;Fe batteries.

Methods for forming magnetically modified electrodes and articles produced thereby

The present invention is directed to methods for determining electron transfer rates in systems involving metalloproteins. Metalloprotein/substrate electron transfer rates as well as metalloprotein self exchange rates may be modeled. Such electron transfer rates are useful in smart drug design and enzyme engineering.

Methods for determining electron transfer rates in metalloproteins

New magnetic materials and new metallic particles, new methods of making and using same, for example, to prepare magnetically modified electrodes and fuel cells, and coated metallic particles in general. The present invention discloses methods of preparation of cheaper and more uniformly sized magnetic and metallic microparticles formed from the exemplary materials magnetite, nickel, samarium cobalt and neodymium iron boron. In addition, the present invention discloses methodology for preparation and use of coated magnetic and metallic microparticles, in particular, exemplary siloxyl coating of magnetic particles, metallic particles, and magnetic and metallic microparticles with an exemplary silane, 3-aminopropyltrimethoxysilane, that is cross linked thereon. In addition, methods and results are described for preparing and using larger siloxyl coated samarium cobalt milliparticles. Coated magnetic milliparticles and magnetic microparticles are useful as component of composites that are applied to electrodes to alter electrochemical fluxes across those electrodes, as well as to alter chemical reactions on surfaces of those electrodes, when magnetically susceptible reactions occur there.

Growing community of inventors

Iowa City, IA, United States of America

Johna Leddy