MY RESEARCH PROGRAM FOCUSES ON DEVELOPING FUNDAMENTAL UNDERSTANDING OF TRANSPORT of molecules and ions in porous membranes, sorbents, catalysts and related materials on a broad range of microscopic length scales between around 100 nm and tens of microns. Such materials usually exhibit complex and, in some cases, even hierarchical structure that results in different transport properties on different microscopic length scales. Understanding the complexity of microscale transport in these materials on a fundamental level is required for optimizing their performance in separations and catalysis. For such studies, we develop and apply nuclear magnetic resonance (NMR) techniques that benefit from combining advantages of high magnetic field and high magnetic field gradients.
MICROSCOPIC GAS TRANSPORT IN GAS-SEPARATION MEMBRANES AND CATALYSTS An application of a unique diffusion NMR technique, pulsed field gradient (PFG) NMR at high magnetic field and large magnetic field gradients resulted in the first direct measurements of microscale transport of gas molecules in mixed matrix membranes (MMMs) and carbon molecular sieve (CMS) membranes as well as in aerogel and nanoporous gold catalysts. In particular, for MMMs, which are formed by dispersing fillers, such as metal-organic frameworks (MOFs) in polymeric matrices, it was possible to resolve diffusion inside MOF particles from diffusion in the polymer phase between the particles. My group has proposed and validated experimentally an analytical expression for the long-range diffusivity in MMMs.
SINGLE-FILE DIFFUSION OF GAS MIXTURES Diffusion in one-dimensional channels so narrow that they forbid mutual passage of molecules is referred to as single-file diffusion. My group was the first to report an experimental observation of single-file diffusion of molecular mixtures, an important result for applications in separations and catalysis. The relationship between the transport rates of mixtures and the corresponding pure components was found to be qualitatively different under the single-file conditions in comparison to normal diffusion. A model-based explanation of this difference was proposed.
Habilitation, Leipzig University, Germany, 2003
Ph.D., Institute of Chemical Kinetics and Combustion, Russia, 1994
M.S., Novosibirsk University, Russia, 1989
Awards & Distinctions
- German Science Foundation (DFG) Mercator Fellowship, 2018
- University of Florida Herbert Wertheim College of Engineering Teacher of the Year Award, 2018
- University of Florida Term Professorship, 2017
- Hanse-Wissenschaftskolleg Senior Fellowship, Germany, 2015
- National Science Foundation CAREER Award, 2010
- University of Florida College of Engineering Teacher of the Year Award, 2010
- Forman, E.M.; Pimentel, B. R.; Ziegler, K. J.; Lively, R.; Vasenkov, S., Microscopic diffusion of pure and mixed methane and carbon dioxide in ZIF-11 by high field diffusion NMR. Microporous and Mesoporous Materials 2017, 248, 158-163.
- Dutta, A. R.; Sekar, P.; Dvoyashkin, M.; Bowers, C. R.; Ziegler, K. J.; Vasenkov, S., Single-file diffusion of mixed gases in nanochannels of the dipeptide L-Ala-L-Val: High field diffusion NMR study. Phys. Chem. C 2016, 120, 9914−9919.
- Mueller, R.; Hariharan, V.; Zhang, C .; Lively, R.; Vasenkov, S., Relationship between mixed and pure gas self-diffusion for ethane and ethene in ZIF-8/6FDA-DAM mixed-matrix membrane by pulsed field gradient NMR. Journal of Membrane Science 2016, 499, 12-19.
- Dutta, A. R.; Sekar, P.; Dvoyashkin, M.; Bowers, C. R.; Ziegler, K. J.; Vasenkov, S., Relationship between single-file diffusion of mixed and pure gases in dipeptide nanochannels by high field diffusion NMR. Chemical Communications 2015, 51 (69), 13346-13349.
- Mueller, R.; Zhang, S.; Klink, M.; Baumer, M.; Vasenkov, S., The origin of a large apparent tortuosity factor for the Knudsen diffusion inside monoliths of a samaria-alumina aerogel catalyst: a diffusion NMR study. Physical Chemistry Chemical Physics (PCCP) 2015, 17 (41), 27481-27487.