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Larry Anderson

Larry Anderson

Larry Anderson

anderson.45@osu.edu

Bio

Professor Anderson received his B.S. degree in Chemistry (1959) from the University of Washington and his Ph.D. (1964) from Syracuse University. He was a research associate at University of North Carolina from 1964-65.

Research Overview

We are interested in the measurement of charge transfer processes at electrodes and in the fate of the chemical products formed during electrolysis. The following descriptions of three problem areas can illustrate these interests.Perhaps the most universally applicable detector for the products of an electrode reaction is a second, independently controlled electrode. That which is produced by electrolysis can usually be detected by electrolysis. We have created filar micro electrodes, separated by a few microns, with the techniques of vapor deposition, photolithography, and etching used in the microelectronics industry. The solution soluble products created by one electrode can be detected at the second electrode within a few milliseconds, and steady state currents are achieved within a few seconds. Spectroelectrochemistry, using filar electrodes, was used to study the blue copper protein, plastocyanine. A second technique we have used for measurement of electrode products is mass spectrometry, which is sensitive enough to measure nanomolar concentrations of volatile compounds in aqueous solution. The catch is that an analytical separation is necessary to remove the electrochemical solvent and electrolyte before the volatile solutes can be introduced into the source vacuum of the mass spectrometer.This problem was solved by carrying out electrolysis at the surface of a 25-micron-thick silicone rubber membrane, which is virtually impermeable to the solvent and electrolyte. Solutes partition into the membrane and diffuse through and evaporate into the M.S. source for analysis.A closely spaced array of electrode filaments behaves as a coarse grating, when illuminated with collimated monochromatic light. When electrolysis at such a filar array creates a colored electrolysis product, a second, absorption grating is created in the solution phase adjacent to the electrode array. This second grating is transient; that is, it is rapidly dispersed by diffusion into the bulk solution, and therefore light diffracted by the transient grating may be used to study diffusion rates of the electrode products. Our program is to study the fundamental properties of electrochemically generated transient gratings and to develop this understanding into useful analytical sensors.