Research Interests
Atmospheric chemistry

In Progress
Aging transformations of atmospheric soot nanoparticles
Major goals of this project are to understand how different coating structures form on soot nanoparticles during atmospheric aging, determine how the coating induces restructuring of soot nanoparticles, and measure/predict light absorption and scattering by the modified soot.

Chemistry of atmospheric mercury
The project goal is to understand the chemistry and speciation of atmospheric mercury, a persistent and bioaccumulative pollutant emitted to the atmosphere in large quantities by coal-fired power plants. Specific objectives are the gas-phase oxidation of mercury, the interaction of oxidized mercury with atmospheric aerosols, and the development of new detection technique for atmospheric oxidized mercury based on the chemical ionization mass spectrometry.

Compressibility of nanopore-confined liquids probed by ultrasonic experiments
This project explores the effects of confinement on compressibility of fluids by means of adsorption-ultrasonic experiments. When fluids are confined in nanopores, many of their physico-chemical properties (e.g. density, freezing point, diffusivity) change as compared to bulk. Some experimental studies suggested that compressibility of confined fluids might also deviate from that in bulk. A series of recent molecular simulation studies, including the work by Gennady Gor, confirmed these observations for nitrogen and argon, and predicted that the departure of compressibility progressively increases with the decrease of the pore size. This let us hypothesize that confinement will change the elastic properties of all fluids when the pore size is comparable to the molecular size, and the extent of this change is determined by the pore size and strength of the solid-fluid interactions. Here we are testing this hypothesis experimentally, as well as explore the effects of other parameters, such as the properties of pore surface, molecular shapes, etc. We also investigate whether confinement can lead to appearance of the shear modulus absent in bulk fluids. We expect that the results of these experiments will complement the current and future molecular simulation studies by Gennady Gor’s group.

Multiscale Modeling of Restructuring of Atmospheric Soot
Soot is a major environmental pollutant with impacts ranging from air quality and human health to climate. The extent of these impacts depends on the microstructure of soot nanoparticles and their surface properties. The soot microstructure is complex, with nanoparticles being fractal aggregates of graphitic spherules mixed with organic and inorganic combustion products or other atmospheric chemicals. On top of it, soot nanoparticles often change structure when interacting with chemicals adsorbed on their surface. The main goal of this project is to develop a molecular-based model for soot nanoparticles restructuring (Gor's group) and verify it against experimental measurements (Khalizov's group).


Awards & Honors
2016 NSF CAREER: Molecular Mechanism of Atmospheric Mercury through Speciation-Resolved Experiments, National Science Foundation

2016 Rising Star Research Award, College of Sciences and Liberal Arts, New Jersey Institute of Technology

2012 Dean's Distinguished Achievement Award , College of Geosciences, Texas A&M

2012 Research Productivity Award , Department of Atmospheric Sciences, Texas A&M

2000 NATO-NSERC Postdoctoral Science Fellowship , NATO-NSERC