Computer simulations of nucleation of nanoparticle superclusters from solution

Area of Science:

• Materials Science
• Chemical Physics
• Nanotechnology

Background:

• Nanoparticle supercluster (NPSC) formation is crucial for advanced materials.
• Understanding nucleation mechanisms is key to controlling NPSC assembly.

Purpose of the Study:

• To simulate and analyze the nucleation process of nanoparticle superclusters.
• To investigate the role of interparticle potentials in NPSC formation.
• To compare simulation results with classical nucleation theory.

Main Methods:

• Utilized simulation studies of nanoparticle supercluster (NPSC) nucleation.
• Employed a system with temperature quenching.
• Modeled 5 nm spherical gold nanoparticles with alkane thiol ligands.
• Incorporated van der Waals interactions for core-core, ligand-ligand, and ligand-solvent interactions.

Main Results:

• Observed phenomena consistent with classical nucleation theory, including induction periods and critical nucleus size.
• Identified that only the largest prenucleating clusters are dense.
• Noted that cluster size can exceed critical size in the prenucleation stage.
• Discovered late-stage clusters exhibit a random mix of face-centered cubic (fcc) and hexagonal close-packed (hcp) lattices, resembling randomized icosahedra.

Conclusions:

• Simulation results align with classical nucleation theory for NPSC formation.
• The study elucidates complex cluster dynamics during nucleation.
• The final crystalline structure of NPSCs is a disordered mix of fcc/hcp lattices.