The Penn group focuses on the fundamental growth mechanisms of a wide range of environmentally and technologically important nanoparticles, with the goal of controlling particle size and shape, the distribution of elements throughout each particle, defect concentration, and aggregation state. Potential applications include materials for solar cells, catalysis, and environmental remediation.
Some of the well-characterized materials are used in experiments aimed at elucidating the links between the physical and chemical properties of the nanomaterials and their chemical reactivity, magnetism, and other properties. For example, the group employs 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, natural materials are used in parallel experiments so as to enable meaningful comparisons between the natural and model materials in environmentally relevant reactions.
The Penn group has four major areas:
elucidating fundamental, particle-mediated crystal growth mechanisms,
characterizing chemical reactivity and evolving reactivity of nanoparticles in environmental systems,
synthesizing nanomaterials using green chemistry and nature as guides, and
designing and implementing effective programs focused on the atomic structure of solid materials and nanotechnology for middle and high school students and teachers.
