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Fabricating High-viscosity Droplets using Microfluidic Capillary Device with Phase-inversion Co-flow Structure
Published on: April 17, 2018
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Nucleation in a liquid droplet.
1Materials Program, Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA. fyang2@uky.edu.
Physical Chemistry Chemical Physics : PCCP
|May 5, 2020
Summary
Researchers derived analytical expressions for free energy changes during nanocrystal synthesis in microfluidic droplets. This work clarifies the critical nucleation number for concurrent formation of multiple microclusters.
Area of Science:
- Nanotechnology
- Materials Science
- Physical Chemistry
Background:
- Droplet-based microreactors in microfluidic systems are utilized for synthesizing various metal and semiconductor nanocrystals.
- Nanocrystal synthesis involves complex nucleation and growth processes within confined environments.
Purpose of the Study:
- To derive analytical expressions for Gibbs and Helmholtz free energy changes during concurrent microcluster formation in stationary droplets.
- To determine the critical nucleation number for simultaneous nucleation of same-sized nuclei.
Main Methods:
- Derivation of analytical expressions for free energy changes (Gibbs and Helmholtz) considering limited solvent and solute atoms.
- Analysis of free energy dependence on the ratio of microclusters to solvent atoms and interface energy.
- Calculation of critical nucleation number based on free energy approximations.
Main Results:
- Both Gibbs and Helmholtz free energy changes depend on the microcluster-to-solvent atom ratio and interface energy.
- The critical nucleation number is influenced by the ratio of nuclei to solvent atoms within the droplet.
- Maximum free energy change for concurrent nucleation increases with the nuclei-to-solvent atom ratio.
Conclusions:
- The study provides a theoretical framework for understanding concurrent nucleation in microfluidic synthesis.
- The derived critical nucleation number is crucial for controlling nanocrystal formation in droplet microreactors.
- Findings offer insights into optimizing nanocrystal synthesis by managing droplet composition and interface properties.
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