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11:54
Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles
Published on: June 25, 2018
Small changes in particle-size distribution dramatically delay and enhance nucleation in hard sphere colloidal
Hans Joachim Schöpe1, Gary Bryant, William van Megen
1Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, D-55128 Mainz, Germany.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|February 7, 2007
Summary
Small increases in polydispersity dramatically alter hard-sphere crystallization kinetics. Even a 1% change delays crystallization by a decade, yet enhances nucleation rates significantly, suggesting polydispersity-limited growth.
Area of Science:
- Physical Chemistry
- Materials Science
- Colloid Science
Background:
- Crystallization kinetics are crucial for understanding material formation.
- Polydispersity, the distribution of particle sizes, can significantly influence phase transitions.
- Previous studies have explored monodisperse systems, but the impact of slight polydispersity remains less understood.
Purpose of the Study:
- To investigate the effect of small variations in polydispersity on hard-sphere crystallization kinetics.
- To quantify changes in crystallization time, nucleation, and growth.
- To elucidate the underlying mechanisms, such as polydispersity-limited growth.
Main Methods:
- Synthesis and characterization of three hard-sphere colloidal samples with incrementally increasing polydispersity.
- In-situ monitoring of crystallization using techniques like dynamic light scattering or video microscopy.
- Analysis of crystallization kinetics, including induction times and growth rates.
Main Results:
- A 1% increase in polydispersity caused a delay in crystallization by nearly a decade.
- Significant quantitative and qualitative changes in the crystallization pathway were observed.
- Nucleation rate density unexpectedly increased by approximately a factor of 10.
Conclusions:
- Polydispersity plays a critical role in dictating crystallization dynamics.
- The observed phenomena can be explained by polydispersity-limited growth and local fractionation.
- These findings highlight the sensitivity of colloidal crystallization to particle size distribution.
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