 Professor B.S. 1980, University of Wisconsin - Madison Ph.D. 1985, Cornell University Room: 3345Phone: 608-262-6371 Email: hamers@chem.wisc.edu Position: Professor Selected Publications
| Research Description
Research in the Hamers group is focused on understanding the properties of surfaces and using this information to control interfaces between various types of organic and inorganic materials. Most of our current work addresses surface/interface chemistry issues relevant to renewable energy and/or to biomaterials interfaces. Much of this work is based on the use of nanoscale materials, with a particular emphasis on understanding how to use molecular layers, often a single molecule thick, to link highly functional objects such as catalytic or photocatalytic centers, biomolecular recognition sites, or quantum-confined nanoparticles, to their surfaces. Interface Chemistry for Renewable Energy: Renewable energy technologies field such as photovoltaic energy conversion, photocatalysis, fuel cells (electrocatalysis), and electrochemical energy storage all hinge on being able to control the transfer of electrons across interfaces between different materials. We are especially interested in developing and using "ultra-stable" surface chemistries to control chemical selectivity and electron-transfer properties at interfaces. Carbon-based materials (diamond, carbon nanofibers) and transition metal oxides (TiO2, ZnO, ZrO2) play especially particularly important roles because the chemical, electrochemical, and thermal stability of these materials allows them to be used in a wide range of environments. Biomolecular and Biomaterials Interfaces: A second aspect to our research is the development of ultra-stable surface chemistries for controlling the interaction of DNA, proteins, and other biological species with materials. We are investigating the use of nanocrystalline diamond, amorphous carbon films, and metal oxides as materials for selective capture of biological molecules in solution. By taking advantage of the semiconducting and/or electromechanical properties of these materials, we are creating new types of biosensing devices in which the biomolecular recognition process generates an electrical or electromechanical response, essentially achieving direct bio-to-electronic signal conversion. Metal oxides such as TiO2 and ZrO2 are extremely stable and form naturally as coatings on Ti and Zr metals, which are widely used in biomedical applications. The oxides are transparent, leading to the ability to provide a high degree of (bio)chemical functionality on transparent materials. Environmental Impact of Nanomaterials: The explosion of interest in nanotechnology has raised questions about the possible environmental safety and health issues surrounding the potential release of engineered nanoparticles into the environment. Nanoparticles are often stabilized by ligands on their surfaces. By understanding how nanoparticles are altered by environmental exposure and how the resulting alterations affect their bioavailability and toxicity, this work will enable the design of nanomaterials with improved safety. This research is carried out as a collaboration with researchers in the Environmental Toxicology Program, the Department of Pharmacy, and other departments. Our group spans a range from very fundamental studies of surface chemical reactions and reaction mechanisms, to the practical applications of these materials to important problems in renewable energy and biomaterials. The work is interdisciplinary in scope, and students from all areas of chemistry are welcome.
Awards
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Vertically aligned carbon nanofibers (VACNFs) are a unique form of carbon that has very high electrochemical activity because of their unique nanoscale structure, consisting of nested cups of 2-dimensional graphite sheets, exposes highly reactive "cut bonds" along the sidewalls that can be used as attachment points for catalysts. Metal oxides are of great interest for solar energy applications such as photovoltaic and solar-to-fuel conversion, using sunlight to drive chemical reactions. Our work involves a blend of studies on single-crystal samples and nanocrystalline materials.