Complex patchy colloids shaped from deformable seed particles through capillary interactions

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Soft Matter Physics

Background:

• Colloidal recycling is a method for fabricating complex particles.
• Capillary forces drive the reconfiguration of spherical aggregates.
• Particle deformability influences the outcome of reconfiguration.

Purpose of the Study:

• To investigate how capillary forces and particle deformability affect the reconfiguration of sphere aggregates.
• To understand the mechanisms for creating various patchy particles using colloidal recycling.
• To determine the relationship between crosslink density and particle shape.

Main Methods:

• Systematically varying the crosslink density of spherical seed particles.
• Analyzing the influence of capillary forces on particle clusters.
• Characterizing the shape and arrangement of resulting patchy particles.

Main Results:

• Increasing crosslink density preserves sphere shape, yielding well-defined patchy particles up to five spheres.
• The aspect ratio (L/W) of dumbbells increases with crosslink density.
• Particle deformability dictates patch arrangement in larger clusters (e.g., octahedral vs. polytetrahedral for six spheres).
• Seven-particle clusters show a preference for pentagonal dipyramids with rigid spheres.
• Larger clusters (>15 particles) form non-uniform, often aspherical shapes.

Conclusions:

• Particle deformability is the key factor governing the reconfiguration pathway in colloidal recycling.
• Confinement and geometric constraints also influence the reconfiguration process.
• This study provides insights into designing complex patchy particles through controlled deformation.