Slippery diffusion-limited aggregation

Colloidal particles that interact through strong, short-range, secondary attractions in liquids form irreversible “slippery” bonds that are not shear-rigid. Through event-driven simulations of slippery attractive spheres, we show that space-filling fractal clusters still emerge from the process of “slippery” diffusion-limited aggregation (DLA). Although slippery and classic DLA clusters have the same fractal dimension, d_f=2.5, their average coordination numbers are quite different: ⟨z_S⟩=6 whereas ⟨z_C⟩=2. Local tetrahedral attractive jamming of the particles leads to a structure factor, S(q), that exhibits dense cluster peaks at higher wave numbers, q, and a fractal power-law rise toward lower q.