Computational self-assembly of colloidal crystals from Platonic polyhedral sphere clusters

Area of Science:

• Colloid science
• Materials science
• Crystallography

Background:

• Colloidal crystals offer tunable properties.
• Self-assembly of complex structures is challenging.
• Polyhedral sphere clusters (PSCs) are novel building blocks.

Purpose of the Study:

• Investigate self-assembly of crystals from PSCs.
• Explore phase behavior of different polyhedral PSCs.
• Characterize crystalline order in core and halo particles.

Main Methods:

• Brownian dynamics simulations.
• Utilized purely repulsive inter-particle interactions.
• Analyzed crystalline order via particle positions.

Main Results:

• Eight distinct crystalline phases self-assembled from five Platonic solid-based PSCs.
• Strong ordering observed in PSC centers of mass (core particles).
• Octahedral and icosahedral PSCs yielded well-ordered halo particles, forming nested structures.

Conclusions:

• PSCs can form complex colloidal crystals with symmetries not achievable by spheres alone.
• Tetrahedral PSCs did not self-assemble but formed stable crystals when pre-assembled.
• Simulated structures mimic faceted polyhedra interactions, despite rounded PSCs.