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Role of Interfacial Processes in Accelerated Reactions in Nano- and Microdroplets
Shu Yang1, Meng Li2, Justin Wang2
1Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States.
The Journal of Physical Chemistry. A
|July 4, 2025
Summary
Microconfinement accelerates reaction kinetics. A new model reveals how evaporation and reaction compete, determining optimal droplet size for chemical processes in microdroplets.
Area of Science:
- Physical Chemistry
- Chemical Engineering
- Materials Science
Background:
- Interfacial processes critically influence reaction kinetics within confined microenvironments.
- Understanding reaction dynamics in microdroplets is essential for various chemical and biological applications.
Purpose of the Study:
- To develop a kinetic model for microdroplet reactions, incorporating diffusion, adsorption, evaporation, partitioning, and surface reactions.
- To generalize the model across a wide range of droplet sizes (nanometer to millimeter).
- To investigate the interplay between reaction and transport processes and its effect on kinetics.
Main Methods:
- Developed a comprehensive kinetic model for microdroplet reactions.
- Utilized tensiometry measurements to parameterize adsorption kinetics with a Langmuir adsorption model.
- Validated the model against experimental data for pyruvic acid condensation to zymonic acid.
Main Results:
- The model quantitatively reproduced experimental observations of concentration and droplet size evolution.
- Demonstrated diverse kinetic behaviors across different droplet sizes due to varying reaction-transport interplay.
- Identified an optimal droplet size driven by the competition between evaporation and reaction.
Conclusions:
- The developed model provides insights into complex microdroplet reaction kinetics.
- General mechanisms governing reaction kinetics in droplets across various scales have been elucidated.
- Findings highlight the critical role of droplet size in determining reaction efficiency and pathways.
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