About
Saptarsi Mondal
My research is driven by a central question: how does the local hydrogen-bond and solvation environment govern transport and reactivity? Because steady-state methods such as FTIR, Raman and NMR average over many of the molecular motions of interest, I use ultrafast vibrational spectroscopy to resolve those dynamics directly. Conventional two-dimensional infrared (2D IR) spectroscopy gives access to bulk electrolyte and solution dynamics, while surface-enhanced 2D IR and SEIRAS allow me to probe the corresponding behaviour at metal–liquid interfaces under operating conditions. Using related molecular reporters in the bulk and at interfaces lets me identify how confinement, electrodes and optical environments modify molecular behaviour.
During my PhD at the Indian Association for the Cultivation of Science with Prof. Prashant Chandra Singh, I combined infrared spectroscopy, molecular dynamics and quantum chemistry to study weak noncovalent interactions in fluorinated and atmospherically relevant systems. At Korea University's Center for Molecular Spectroscopy and Dynamics with Prof. Minhaeng Cho, I studied water structure in biocompatible polymers, free-volume elements in amorphous polymers, ion transport in lithium-ion electrolytes, and wavelet-based denoising methods for ultrafast spectroscopy. At the University of Michigan with Prof. Kevin J. Kubarych, I investigated enzyme catalysis under vibrational strong coupling.
I am now a postdoctoral researcher with Prof. Carlos R. Baiz at the University of Texas at Austin. These experiences inform my current work on interfacial electrochemistry, confined electrolytes and polaritonic chemistry using ultrafast vibrational spectroscopy.
How the work developed
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2024–present
The University of Texas at Austin
Postdoctoral Researcher
I measure hydrogen-bond dynamics of water at plasmonic electrode surfaces by surface-enhanced two-dimensional infrared spectroscopy, and study how plasmonic nanocrystal metasurfaces and optical cavities alter molecular vibrational behaviour.
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2023–2024
University of Michigan
Postdoctoral Researcher
I worked on enzyme catalysis under vibrational strong coupling, placing environmentally and biologically relevant reactions inside an optical cavity and using 2D IR to test whether hybridising a molecular vibration with a cavity mode changes how the reaction proceeds.
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2019–2023
Korea University
Research Professor
I worked on four connected problems: water structure in biocompatible polymers and hydrogels, free-volume elements in amorphous polymers, ion transport in lithium-ion electrolytes and separators, and a wavelet-based denoising method for ultrafast spectroscopy. Here my work moved from noncovalent interactions in bulk liquids toward confined and functional environments.
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2018
RIKEN
Visiting Researcher
A short visiting appointment in which I used heterodyne-detected vibrational sum frequency generation spectroscopy to study how DNA reorganises water at lipid membrane interfaces. It was my first work on an interfacial rather than a bulk system.
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2013–2018
Indian Association for the Cultivation of Science
PhD, Chemistry
My doctoral work combined infrared spectroscopy, molecular dynamics simulation and quantum chemistry to understand weak noncovalent interactions: organic fluorine as a hydrogen-bond acceptor, dispersive fluorous contacts, and the unconventional bonding in hydrated carbonyl sulfide clusters. It led to fourteen publications, several as first author.
Research directions
Interfacial electrochemistry, confined electrolytes and polaritonic chemistry share the same instrumentation and the same analysis framework, and each depends on how hydrogen-bond and solvation dynamics behave near a boundary.
I plan to build a laboratory around voltage-dependent surface-enhanced 2D IR and operando SEIRAS. The first directions, cosolvent- and potential-controlled electrocatalysis and operando battery-separator dynamics, extend published work. The polaritonic experiments carry more risk, so I will pursue them in stages and attempt the enzyme experiments only after a coupling effect has proved reproducible in my own measurements.
I also look forward to training students in ultrafast spectroscopy, electrochemistry and materials chemistry, an overlap I have had to learn across several laboratories.