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Updated: Jun 24, 2025
07:02
Studying the Effects of Temperature on the Nucleation and Growth of Nanoparticles by Liquid-Cell Transmission Electron Microscopy
Published on: February 17, 2021
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Latent-to-sensible heat conversion kinetics during nanoparticle coalescence.
Abhilash Ojha1, Tomoya Tamadate2, Christopher J Hogan1
1Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
The Journal of Chemical Physics
|June 4, 2024
Summary
Nanoparticle coalescence releases significant heat, increasing their temperature by hundreds of Kelvin. This internal kinetic energy evolution depends heavily on the surrounding gas environment, not just surface area changes.
Area of Science:
- Physical Chemistry
- Materials Science
- Nanotechnology
Background:
- Coagulational growth in aerosols involves particle collision and coalescence.
- Previous studies often assumed isothermal or constant energy processes during coalescence.
- Internal kinetic energy changes during coalescence are influenced by bond formation and heat transfer.
Purpose of the Study:
- To develop and test a model for internal kinetic energy evolution in coalescing nanoclusters.
- To investigate the role of background gas in heat transfer during coalescence.
- To understand the relationship between coalescence kinetics and energy dynamics.
Main Methods:
- Developed a model for internal kinetic energy evolution in collisionally formed nanoclusters.
- Incorporated a power law for latent-to-sensible heat release and a modified thermal accommodation coefficient.
- Tested the model against atomistic simulations of gold nanocluster sintering in argon and helium.
Main Results:
- Nanocluster effective temperatures can increase by hundreds of Kelvin due to coalescence.
- Internal kinetic energy dynamics follow a power law and depend on the background gas environment.
- Internal kinetic energy change kinetics differ from surface area change kinetics.
Conclusions:
- The developed model accurately predicts internal kinetic energy evolution during nanocluster coalescence.
- Background gas significantly impacts the rise and re-equilibration of internal kinetic energy.
- Modeling heat release solely based on surface area change is insufficient for accurate coalescence studies.
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