Synthesis of single and multipatch particles by dip-coating method and self-assembly thereof

Area of Science:

• Materials Science
• Colloid Science
• Surface Chemistry

Background:

• Patchy particles are crucial for designing complex colloidal structures.
• Existing methods for producing patchy particles often face limitations in scalability and control.

Purpose of the Study:

• To develop a simple and scalable dip-coating strategy for synthesizing single and multipatch silica particles.
• To investigate the influence of process parameters on patch characteristics (shape, size, number).
• To explore the self-assembly behavior of these synthesized patchy particles.

Main Methods:

• Formation of a close-packed monolayer of silica particles at an air-polymer interface.
• Dip-coating the particle monolayer onto a glass substrate with a polymer solution.
• Sonication of the substrate to induce polymeric patch formation on particles.
• Characterization using scanning electron and optical microscopy.
• Controlled variation of polymer concentration and particle surface coverage.

Main Results:

• Successful production of single and multipatch silica particles via dip-coating.
• Demonstrated control over patch shape (ring-like to disk-like) by polymer film aging.
• Tunable patch width through polymer concentration and number of patches via particle concentration.
• Observation of particle self-assembly into doublets and finite clusters driven by patchy interactions.

Conclusions:

• The dip-coating method provides a scalable and controllable route to synthesize diverse patchy particles.
• The synthesized particles serve as a valuable model system for fundamental studies in colloidal self-assembly.
• This technique overcomes limitations of previous methods, paving the way for large-scale production.