Research Openings
Fundamentals of Spray Coating (posted 6/12/2007): Applicants are sought for a postdoctoral position involving fundamental research in spray coating. This position, which will be be based in the Department of Chemical Engineering and Materials Science at the University of Minnesota, is part of the industrially supported Coating Process Fundamentals Program and will be jointly supervised by Profs. Lorraine Francis and Satish Kumar.
Spray coating is used to create coatings on irregularly shaped objects, ranging from cereal flakes to cardiovascular stents. In spray coating, liquid droplets are generated, travel through the air, impact a substrate, and somehow coalesce with other droplets to form a continuous liquid layer. Drying and curing may then lead to structural changes that are controlled by the chemical composition of the coating liquid. Ultimately, the final microstructure and properties of the coating depend on the entire sequence of steps.
In this project, high-speed visualization will be combined with cryo-microscopy and other probes to map out the evolution of the microstructure and various physical properties, with an initial focus on the impact and coalescence steps. These experimental studies will be complemented by mathematical modeling. Opportunities exist to draw upon and integrate a number of fields including fluid dynamics, rheology, and materials science. Applicants with a background and interest in any of these fields, and a willingness to actively interact with industrial researchers, are encouraged to apply by sending a CV and the names of two references to Prof. Kumar (kumar@cems.umn.edu) or Prof. Francis (lfrancis@umn.edu). The initial appointment will be for one year, with the possibility of renewal for a second year.
Development of Coating Properties During Solidification (with Prof. McCormick) (Available Fall, 2008): As a polymer coating dries or cures, its viscosity climbs and elastic properties develop. The goal of this project is to characterize these property changes and connect results to ongoing research in stress development and microstructure development. The project will begin with a critical assessment of characterization methods and selection of model materials systems. The results of the research will impact a wide variety of coatings.
Microstructure Development in Coatings – Multiple Probes (Available Fall, 2008): Often the key features of coating microstructure form during drying or curing. The development of microstructure is dynamic. Capturing the changes with time aids in designing the coating compositions and process conditions that lead to the desired microstructure and properties. In this project, cryogenic SEM will be used in combination with other microstructural probes such as confocal microscopy, drying studies, RAMAN and FTIR spectroscopies and stress measurement.