Research Interests
The overall theme of my research is the investigation of chemical and physical phenomena occurring in advanced materials and non-traditional solvents, particularly environmentally benign solvents, with an emphasis on energy, the environment, and sustainability. This research involves both multi-scale modeling and experiments. Our modeling efforts include computational quantum chemistry, molecular simulation, and mechanistic modeling.
Reactions in Supercritical Fluids
Supercritical water oxidation (SCWO) is a process that oxidizes organic compounds in an aqueous environment above the critical point of water (Tc=374 C, Pc = 218 atm). Part of the ongoing research in this area involves the creation of mechanism-based detailed chemical kinetics models (DCKMs) to describe SCWO chemistry at a fundamental level. We are pursuing research in this arena by exploring nitrogen-based chemistry in supercritical water (SCW). In particular, we are seeking to construct a DCKM for methylamine SCWO. This effort, done in collarboration with Dr. Justin Meyer (Meyer, Justin P - Assistant Professor) involves performing quantum chemical calculations to determine the kinetics and thermodynamics of elementary free-radical reactions involved during methylamine (CH3NH2) oxidation in SCW.
Transition state for the reaction ,
an important reaction during low-temperature supercritical water oxidation of amines.
The kinetic and thermodynamic parameters from these quantum chemical calculations serve as input to a large, free-radical based reaction mechanism that is used to simulate the reaction chemistry of methlyamine oxidation in SCW and in the gas-phase.
Properties of Benign Solvents via Molecular Simulation
Green chemistry, or sustainable technology, is emerging as an important area of chemical processing. Broadly defined, green chemistry “efficiently utilizes (preferably renewable) raw materials, eliminates waste and avoids the use of toxic and/or hazardous reagents and solvents in the manufacture and application of chemical products”. To this end, reactions conducted in a variety of unique, yet environmentally friendly, solvents such as ionic liquids, gas-expanded liquids, and high-temperature water have attracted much interest for a variety of synthetic chemistries.
One facet of furthuring green chemistry in environmentally benign solvents is to determine relevant thermodynamic and transport properties of these solvent systems. Our major research tool here is molecular simulation, including both molecular dynamics and Monte Carlo methods.
Properties of water clusters (trimer shown here) via molecular simulation.
Nanoparticle Processing in Non-Traditional Solvents
Here we are using molecular simulation to investigate the self-assembly of nanoparticles in environmentally benign solvents such as supercritical fluids, gas-expanded liquids, and ionic liquids.
Molecular Modeling of Polymeric Self-Assembled Monolayers
Here we are using molecular simulation to investigate the self-assembly of polymeric nanocomposites into monolayers. This work involves understanding both the thermodynamics of self-assembly, including the effect of interphase chemistry, as well as the ultimate effect on the mechanical properties of the nanocomposite. This work is done in collaboration with Dr. Robb Winter (IFM - Robb Winter, PhD).