Interplay between the Formation of Colloidal Clathrate and Cubic Diamond Crystals

Area of Science:

• Materials Science
• Computational Chemistry
• Soft Matter Physics

Background:

• Controlling patchy particle assembly for specific crystalline structures is challenging due to competing phases with similar free energies.
• Existing methods struggle to achieve selectivity, often resulting in mixtures of crystalline structures, glasses, or liquid phases.

Purpose of the Study:

• To investigate the effect of external surface potential on the self-assembly of tetrahedral patchy particles.
• To demonstrate the suppression of bulk assembly behaviors and achieve selective crystal growth.

Main Methods:

• Utilizing molecular dynamics simulations to model the behavior of tetrahedral patchy particles.
• Applying external surface potentials of varying strengths to the system.

Main Results:

• External surface potential can suppress the formation of clathrates and stacking hybrids observed in bulk simulations.
• Selective growth of either cubic diamond crystals or empty sII clathrate cages is achievable by tuning surface potential strength.
• The structure of the initial adlayer dictates the formation of the emergent ordered network.

Conclusions:

• External surface potential offers a powerful tool to direct the self-assembly of patchy particles into desired crystalline architectures.
• This approach overcomes limitations of controlling valency alone, providing a pathway for targeted material design.