Biogeochemistry of Earth Processes

Research Focus

Our Focus:
Mechanistic studies of biomineralization; kinetics and thermodynamics of mineral nucleation and growth and dissolution; surface characterization; interplay of chemical driving force and surface energy in mineral/water reactions; mechanisms and energy barriers to mineral nucleation and growth onto inorganic and biomolecule-functionalized substrates.

Systems:

Studies emphasize a fundamental understanding of the amorphous and crystalline forms of silica and the calcium carbonates. The SiO2 and CaCO3 polymorphs are two of the largest groups of biologically and geologically formed earth materials. Owing to their different bonding and mineral chemistries, covalent and ionic, respectively, each present unique properties and challenges to understanding behavior in earth environments.

Applications:
Fundamental research into the chemical and physical processes of mineral formation and dissolution is a rich scientific area in the earth, materials, medical, and engineering disciplines. Current projects are investigating forefront questions in problems related to biomineralization, cementation, chemical weathering, paleoproxy models, geothermal/petroleum energy, metal and biomolecule interactions with minerals.

Methods:
We use a variety of experimental methods to quantify the kinetics and thermodynamics of the reactions while also directly imaging mineral surfaces to gain mechanistic insights. These techniques include Atomic Force Microscopy, several types of mixed flow reactors, as well as surface characterization instrumentation such as scanning electron microscopy, SIMS, electron microprobe, ESCA, x-ray diffraction, BET areas, and surface charge measurements. In collaborations with Jerry Gibbs, we also conduct ab initio molecular orbital calculations to study bonded interactions and chemical reactivity with an in-house six computer Dell cluster with dual processors.