Characterize chemical reactivity and evolving reactivity of nanoparticles in environmental systems,
Reactions for sulfide remediation in sulfide-contaminated water,
Fate and transport of microplastics,
Oil in water dispersions,
Green materials synthesis for applications related to sustainable energy, and
Development of smartphone based experiments geared towards use in the field and for middle and high school laboratories.
Students in the Penn group use many state-of-the-art materials characterization methods, including in situ and ex situ transmission electron microscopy (TEM), in combination with a broad suite of correlative methods, to characterize solid-state changes resulting from reactions with both natural and anthropogenic chemicals. This enables us to quantitatively assess reactivity, reactive surface area, and how reactivity and reactive surface area evolve as reactions proceed and solution conditions change. In addition, materials collected from the field are used in parallel experiments so as to enable meaningful comparisons between the field and the lab.
Figure caption: Cryogenic transmission electron microscopy of oriented iron oxide nanocrystals in water. The uniform grey background is vitrified water, and the darker round objects are crystals of iron oxide. Images like these enable us to study crystal growth, nanoparticle aggregation, and more. Image is from Yuwono, V.M.; Burrows, N.D.; Soltis, J.A.; Penn, R.L., (2010). Oriented Aggregation: Formation and Transformation of Mesocrystal Intermediates Revealed, Journal of the American Chemical Society, 132, pp. 2163-2165. DOI 10.1021/ja909769a
Biography
Education
B.S. Beloit College, 1992
Ph.D. University of Wisconsin, 1998
Post Doctorate Johns Hopkins University, 1998-2000
