Multiphasic size-dependent growth dynamics of nanoparticle ensembles

Area of Science:

• Materials Science
• Physical Chemistry
• Nanotechnology

Background:

• Colloidal nanoparticles are crucial in science and industry.
• The thermodynamic mechanisms and dynamics of nanoparticle growth remain poorly understood.
• Existing theories fail to explain observed nanoparticle growth behaviors.

Purpose of the Study:

• To investigate the in-situ growth dynamics of nanoparticle ensembles.
• To develop a theoretical model explaining nanoparticle growth mechanisms.
• To elucidate the role of chemical potential in nanoparticle size-dependent dynamics.

Main Methods:

• Tracking hundreds of in-situ growth trajectories using liquid-phase Transmission Electron Microscopy (TEM).
• Developing a novel theoretical model for nanoparticle ensemble growth.
• Analyzing nanoparticle size-dependent multiphasic dynamics and fluctuations.

Main Results:

• Observed nanoparticle growth, including coalescence, exhibits size-dependent multiphasic dynamics.
• Current theories cannot explain these observed dynamics.
• Developed a unified model quantitatively describing nanoparticle size mean, fluctuation, and growth rates.
• Demonstrated significant deviation of chemical potential in small nanoparticles from the Gibbs-Thomson equation.

Conclusions:

• The study provides a quantitative understanding of nanoparticle growth dynamics.
• Revealed that chemical potential deviations govern size-dependent nanoparticle growth.
• The new model offers insights applicable across various nanoparticle systems and conditions.