Raman Spectroscopy Reveals Isotope-specific Hydrogen Bond Kinetics in a Spherical Droplet leading to Preferential Evaporation of D2O in H2O-D2O Mixture
- 1Department of Chemistry
- 2Indian Institute of Technology Guwahati
- 3Centre for Nanotechnology
Abstract
The evaporation of a spherical droplet having a pure solvent or a mixture of isotopic forms is fundamental to atmospheric physics, and critical for studying interfacial fluid dynamics, and hydrogen-bond kinetics. Understanding the hydrogen/deuterium bonded structural dynamics at molecular level during evaporation of isotopic water mixture (H2O/D2O) is important for understanding non-equilibrium phase transitions. In this work, we investigated real-time evaporation kinetics of spherical water droplets on superhydrophobic surface by time - dependent Raman spectroscopic method. Specifically, the results give an account for the variation of each H - or D-bonded clusters (ranging from fully tetrahedral ice-like structure to free water molecule) with time in the mixture from the time - dependent intensity change of each distinct vibrational stretching band of O-H or O-D. For pure H2O, the O-H peak intensities for all the clusters were decreasing with time, whereas for pure D2O, the ice-like structures vanished quickly with simultaneous increase in the free D2O molecules. In the mixture of H2O-D2O, based on Raman signal of each species, our experimental measurements suggested that the species having O-D or D2O was evaporating faster in comparison to the species having O-H or H2O. The results were also supported by the molecular dynamics simulation, which revealed that the bulk D2O was moving to the surface, and evaporating faster than H2O molecules.
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BibTeX
@misc{paul2026raman,
title = {{Raman Spectroscopy Reveals Isotope-specific Hydrogen Bond Kinetics in a Spherical Droplet leading to Preferential Evaporation of D2O in H2O-D2O Mixture}},
author = {Sujay Paul and Dinesh Sharma and Arun Chattopadhyay},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15009987/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009987/v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Raman Spectroscopy Reveals Isotope-specific Hydrogen Bond Kinetics in a Spherical Droplet leading to Preferential Evaporation of D2O in H2O-D2O Mixture
AU - Sujay Paul
AU - Dinesh Sharma
AU - Arun Chattopadhyay
PY - 2026
DA - 2026/10/06
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009987/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009987/v1
AB - The evaporation of a spherical droplet having a pure solvent or a mixture of isotopic forms is fundamental to atmospheric physics, and critical for studying interfacial fluid dynamics, and hydrogen-bond kinetics. Understanding the hydrogen/deuterium bonded structural dynamics at molecular level during evaporation of isotopic water mixture (H2O/D2O) is important for understanding non-equilibrium phase transitions. In this work, we investigated real-time evaporation kinetics of spherical water droplets on superhydrophobic surface by time - dependent Raman spectroscopic method. Specifically, the results give an account for the variation of each H - or D-bonded clusters (ranging from fully tetrahedral ice-like structure to free water molecule) with time in the mixture from the time - dependent intensity change of each distinct vibrational stretching band of O-H or O-D. For pure H2O, the O-H peak intensities for all the clusters were decreasing with time, whereas for pure D2O, the ice-like structures vanished quickly with simultaneous increase in the free D2O molecules. In the mixture of H2O-D2O, based on Raman signal of each species, our experimental measurements suggested that the species having O-D or D2O was evaporating faster in comparison to the species having O-H or H2O. The results were also supported by the molecular dynamics simulation, which revealed that the bulk D2O was moving to the surface, and evaporating faster than H2O molecules.
ER -