Formation and Engineering of Spatiotemporal Structure: Studies in Electrochemistry

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

Research: The PI is investigating the formation and control of spatiotemporal patterns in chemically reacting systems and is thus contributing to the emerging branch of research on the engineering of chemical complexity. The work is largely experimental and is a test-bed for existing idealized theories although a few modeling studies relating to the experiments will also be carried out. The study will add to the fundamental understanding of the interaction of coupling and reaction in chemically reacting systems. The delineation of the relative importance of short-range and long-range coupling has relevance to general chemical reactor design. He is investigating the effects of external signals on developed patterns and the relationship between the imposed temporal scales and resulting spatial scales. A recently discovered phenomenon in chemically reacting systems, the development of clusters in which various regions of a reacting system synchronize but remain different from the remainder of the reaction area, is being investigated in detail; both stationary and temporally varying clusters are to be studied. He is developing addressable arrays and investigating the effects of spatially inhomogeneous forcing and feedback signals on reactions, both metal electrodissolution reactions and electrocatalytic reactions. The input of temporally and spatially varying signals gives improved control over reaction conditions. The relationship between temporal and spatial scales is exemplified and is being exploited in high resolution patterning of metal surfaces with the use of ultra-short voltage pulses. Broader Impacts: The research addresses fundamental issues that are driven by practical applications of commercial importance. Corrosion of metals has a major recurring impact on the national economy. The oxidation of small organic molecules and of hydrogen is of potential importance in several applications including fuel cells and electro-organic synthesis. The ability to manipulate temporal and spatial structures with ultra-short voltage pulses has direct applications in the electrochemical machining of metals. The work on engineered pattern formation can lead to improved reactivity and selectivity in chemically reacting systems. A strong emphasis of these studies is on the training of students. The PI endeavors to broaden the participation of underrepresented groups. At the present time two of his six graduate students are women and in the past ten years three African-American graduate students have completed their PhD studies. The PI is presently associated with a training grant from NIH for minority students along with other faculty at Virginia, Northwestern, and Morehouse. He carries out extensive collaborative studies with international partners in Germany, China, Mexico, and Lithuania; as part of these studies he has an active exchange of graduate students. He plans to continue his participation in presentation of his work in the USA and overseas; this includes workshops organized for students and investigators from third world countries.