Penn Research Group

Environmental Solid State Chemistry  •  Nanocystalline Materials  •  Geochemical Cycling

Major Research Areas

Professor Penn's research group encompasses several areas, many of which involve collaborations with other research groups both at the U of MN - twin cities and beyond:

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

Professor Lee Penn in Characterization Facility

Contact Information

Distinguished University Teaching Professor 

Institute on the Environment Resident Fellow
Mental Health Advocate

rleepenn@umn.edu
(612) 626-4680
225 Smith Hall
they/them

More information about Professor Penn

Black Lives Matter