KNona Liddell

Research Interests

Electropolymerization and Characterization of Conduction Polymers

Conduction polymers have great promise for applications as diverse as sensors, semipermeable membranes and batteries. The porosity of a conducting polymer film is critical in determining the specific uses it might have and depends in part on how the material has been processed. Preparation of copolymers with graded composition is under study as a route to combining desirable electronic properties with controlled morphology. Aniline copolymer films are grown in a novel continuous flow fluidized bed electropolymerization reactor, and their structure and properties characterized by microscopic, electrochemical, impedance and optical techniques. Models for reactor scale-up are in development.

For purposes of comparison with the electropolymerized materials, plasma polymerized films are also being made in collaboration with a team of WSU electrical engineers. Efforts center on fabrication of thin-film capacitors and diodes. The substrate influences the film’s roughness and porosity, and in addition the growth mode depends on film thickness. Early results suggest that the optical properties of plasma-polymerized films may differ from those of films made by other synthetic routes. These effects are being investigated systematically so that film growth models can be obtained.

Electrodeposition of Thin Layer Magnetic Materials

In work related to magnetic data storage, we are electrodepositing layered alloy films and characterizing their morphology and properties. Typical model systems consist of alternating layers of ferromagnetic and nonmagnetic metals, for example, Ni/Cu/Ni trilayers or Co/Cu/Co multilayers. When the thickness of the individual layers is comparable to the mean free path of a conduction electron in a metal, i.e., several nanometers, the films have novel magnetic properties that make them attractive candidates for new generation data storage materials. The roughness of the interface between ferromagnetic and adjacent nonmagnetic regions can be controlled by choosing the deposition conditions and appears to affect the film’s magnetic properties. Our work on Electrodeposited ultrathin films is aimed at elucidating the connections between the electrodeposition process variables, the nanoscale film morphology, and the properties of the films. We are using a combination of experiments and modeling to study the processing, structure, and properties of these films.

Selected Publications

1. Z. Nagy, N.C. Hung, K.C. Liddell, M. Minkoff and G.K. Leaf, “Applicability of dc Relaxation Techniques to Multi-Step Reactions.” J. Electroanal. Chem. 421, 33-44 (1997).
2. Z. Liu and K.C. Liddell, “Electrodeposition of Thin Multilayer Magnetic Materials.” In Aqueous Electrotechnologies: Progress in Theory and Practice. D.B. Dreisinger, Ed., The Minerals, Metals and Materials Society, pp. 443-453 (1997).
3. K.C. Liddell, “Mixing Cell Models for the Separation and Recovery of Metals: Flow with Multiple Reactions in Porous Media.” In Emerging Separation Technologies for Metals II. R.G. Bautista, Ed., The Minerals, Metals and Materials Society, pp. 35-47 (1996). Invited review.
4. J.F. Brantner and K.C. Liddell, “Role of Ion Exchange Reactions in the In Situ Leaching of Uraninite by NH4HCO3 – (NH4)2CO3 – H2O2.” In Light Metals 1996. W. Hale, Ed., The Minerals, Metals and Materials Society, pp. 1169-1172 (1996).
5. K.C. Liddell and R.G. Bautista, “Simulation of In Situ Uraninite Leaching. Part II: The Effects of Ore Grade and Deposit Porosity.” Metall. Mater. Trans. B, 26B, 687-694 (1995).
6. K.C. Liddell and R.G. Bautista, “Simulation of In Situ Uraninite Leaching. Part III. The Effects of Solution Concentration.” Metall. Mater. Trans. B, 26B, 695-701 (1995).
7. K.C. Liddell and R.G. Bautista, “Concentration Histories and Wave Fronts in the In Situ Leaching of Uraninite by Peroxide-Carbonate-Bicarbonate Solution: Effects of Component Concentrations.” In Extraction and Processing of Trace and Reactive Metals. R.G. Reddy and B. Mishra, Eds., The Minerals, Metals and Materials Society, pp. 207-219 (1995). Also in Light Metals 1995. J.W. Evans, Ed., The Minerals, Metals and Materials Society, pp. 1357-1363 (1995).