MY RESEARCH PROGRAM FOCUSES ON DEVELOPING FUNDAMENTAL UNDERSTANDING OF TRANSPORT of molecules and ions in 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.

TRANSPORT-STRUCTURE RELATIONSHIP IN MEMBRANES WITH IONIC PROPERTRIES
Polymer membranes with ionic properties such as the commercially available Nafion® are among the most promising materials in a wide variety of applications including fuel cells, water desalination, chemical sensing, and selective capture of chemical warfare agents (CWA). Molecular and ion diffusion plays an important role in these applications. My group applies advanced NMR techniques to quantify intramembrane transport of liquid sorbates on all relevant microscopic length scales leading to fundamental understanding of transport-structure relationship in this class of materials.

Education

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

selected Publications

• Baniani, A.; Berens, S. J.; Rivera, M. P.; Lively, R. P.; Vasenkov, S., Potentials and challenges of high-field PFG NMR diffusion studies with sorbates in nanoporous media. Adsorption-Journal of the International Adsorption Society 2021,27 (3), 485-501.
• Baniani, A.; Rivera, M. P.; Lively, R. P.; Vasenkov, S., Quantifying Diffusion of Organic Liquids inside MOF Crystals Dispersed in a Polymer to Form Mixed Matrix Membranes by NMR Diffusometry at High Magnetic Fields Journal of Membrane Science 2021, in press, https://doi.org/10.1016/j.memsci.2021.119786
• Berens, S.; Hillman, F.; Hamid, M. R. A.; Jeong, H. K.; Vasenkov, S., Influence of 2-ethylimidazole linker-doping in ZIF-8 crystals on intracrystalline self-diffusion of gas molecules by high field diffusion NMR. Microporous and Mesoporous Materials 2021, 315.
• Berens, S. J.; Yahya, A.; Fang, J. C.; Angelopoulos, A.; Nickels, J. D.; Vasenkov, S., Transition between Different Diffusion Regimes and Its Relationship with Structural Properties in Nafion by High Field Diffusion NMR in Combination with Small-Angle X-ray and Neutron Scattering. Journal of Physical Chemistry B 2020, 124 (40), 8943-8950.
• Forman, E. M.; Baniani, A.; Fan, L.; Ziegler, K. J.; Zhou, E. K.; Zhang, F. Y.; Lively, R. P.; Vasenkov, S., Relationship between ethane and ethylene diffusion inside ZIF-11 crystals confined in polymers to form mixed-matrix membranes. Journal of Membrane Science 2020, 593, 117440.