Lev D. Gelb
Associate Professor of Materials Science and Engineering
Associate Professor of Chemistry, Washington University, 2006-2010
Assistant Professor of Chemistry, Washington University, 2002-2006
Assistant Professor of Chemistry, Florida State University, 1999-2002
1995 PhD, University of Cambridge
1992 BA, Columbia University
In molecular simulation research powerful computers are used to accurately model real systems using statistical mechanics and quantum mechanics. This provides a sort of "virtual laboratory" in which almost any property can be measured or examined, including those which are not accessible to experiments. We use simulations to develop an atomic-scale understanding of the behavior of complex systems. We are currently investigating:
Ab initio Monte Carlo simulation of phase equilibria at extreme conditions.
By coupling widely-used Density Functional Theory electronic structure codes to advanced Monte Carlo simulation algorithms, we can obtain liquid-vapor and liquid-liquid coexistence lines at extremes of temperature and pressure not easily accessed by experiment. We are currently working on phase equilibria in elemental systems, such as lithium metal, lithium/sodium mixtures, phosphorous, sulfur, and carbon.
Multiscale modeling of amorphous porous materials.
Molecular and coarse-grained simulations are used used to develop realistic models of amorphous porous materials, ranging from aerogels to perfluorosulfonic acid (PFSA) membranes to nanocomposite systems. In studies of aerogels and aerogel-based composites, mechanical and thermal properties are of particular interest. PFSA membranes are widely used as the electrolytes in fuel cells. Xerogels and aerogels are nanostructured porous materials prepared using sol-gel processes that can display a wide range of chemical, topological and morphological characteristics. They are extensively used in chromatography, catalysis, optics, biotechnology and chemical sensing.
The relationship between the complex structures of amorphous materials and their useful properties is poorly understood. We address this by developing realistic models of these materials and using them in simulations of important applications. This work requires a multi-scale approach involving: (1) quantum mechanics, used to understand the interactions between precursor species and to parameterize reactive simulation models, (2) molecular simulations, to model the growth and structure of aggregates and mesostructure at short times, and (3) coarse-grained and lattice-type models, to study the large-scale evolution in these materials.
The behavior of gases and liquids in nanometer-scale pores is considerably different than in the bulk, and is important in separation technologies, catalytic reactors, lubrication, nano-scale devices, and materials characterization. Using recently developed simulation methods, we can directly probe the dynamics and thermodynamics of these systems.
- “Isothermal-Isobaric Monte Carlo Simulations of Liquid Lithium Using Density Functional Theory”, L. D. Gelb, T. N. Carnahan*, Chem. Phys. Letts. 417 (2006) 283-287.
- “Simulating Silica Aerogels with a Coarse-Grained Flexible Mode and Langevin Dynamics, L. D. Gelb, J. Phys. Chem. C 111 (2007) 16792-15802.
- “Monte Carlo Simulations Using Sampling from an Approximate Potential”, L. D. Gelb, J. Chem. Phys.118 (2003) 7747-7750.
- “Predicting Gas Adsorption in Complex Microporous and Mesoporous Materials Using a New Density Functional Theory of Finely Discretized Lattice Fluids”, D. W. Siderius and L. D. Gelb, Langmuir 25 (2009) 1296-1299.
- Structure, Thermodynamics and Solubility in Tetromino Fluids, B. C. Barnes, D. W. Siderius and L. D. Gelb, Langmuir 25 (2009) 6702-6716.
- “Phase Separation in Confined Systems, Lev D. Gelb, K. E. Gubbins, R. Radhakrishnan, M. Sliwinska-Bartkowiak, Rep. Prog. Phys. 62 (1999)1573-1659.