Pattern Formation in Binary Colloidal Assemblies: Hidden Symmetries in a Kaleidoscope of Structures

Area of Science:

• Colloid science
• Materials science
• Soft matter physics

Background:

• Binary colloidal systems with size ratios preserving hexagonal order are well-studied.
• Disordered binary colloidal assemblies lack detailed morphological analysis due to complex symmetry recognition.

Purpose of the Study:

• Investigate the morphology of binary colloidal structures at the air/water interface.
• Analyze systems where larger particles disrupt hexagonal arrangements.
• Develop methods to identify hidden symmetries in disordered assemblies.

Main Methods:

• Utilized computational geometry and computational topology tools.
• Examined binary assemblies with varying concentrations of smaller particles.
• Identified patterns and symmetry transitions in disordered arrangements.

Main Results:

• Disordered binary colloidal assemblies exhibit coexisting patterns.
• Increasing small particle concentration leads to transitions from hexagonal to rhombic and square symmetries.
• Small particle clusters increase with rising small particle concentration.

Conclusions:

• Assembly morphology in disordered binary colloids can be controlled by varying composition.
• Computational tools enable the investigation of complex colloidal patterns.
• Findings aid understanding of self-assembly and tailoring of colloidal assembly properties.