Self-Assembly in an Experimentally Realistic Model of Lobed Patchy Colloids

Area of Science:

• Materials Science
• Colloid Science
• Computational Chemistry

Background:

• Lobed colloids self-assemble into porous structures with biomedical potential.
• Experimental synthesis allows tuning of lobe number and position.
• Particle polydispersity (variations in lobe number, size, and position) significantly impacts self-assembly.

Purpose of the Study:

• To investigate the effect of non-uniform lobe sizes (polydispersity) on the self-assembly of lobed colloids.
• To analyze three experimentally relevant lobed particle designs: dumbbell (2 lobes), trigonal planar (3 lobes), and tetrahedral (4 lobes).

Main Methods:

• Coarse-grained Langevin dynamics simulations were employed.
• Simulations were conducted in the NVT ensemble.
• The study extended beyond uniform lobe size conditions.

Main Results:

• Dumbbell systems transitioned from disordered to crystalline structures with increasing polydispersity.
• Trigonal planar systems showed a loss of order in their crystalline structures.
• Tetrahedral systems maintained crystalline structures with minimal loss of compactness.
• Increasing the number of lobes minimized the impact of polydispersity on self-assembled morphology.

Conclusions:

• Polydispersity in lobe size significantly influences self-assembly, with effects varying by particle architecture.
• Increasing lobe number can mitigate the disruptive effects of polydispersity.
• Lobe size polydispersity presents an opportunity to tune self-assembly for specific structures.