Abstract

Low-density networks of molecules or colloids form at low temperatures when the interparticle interactions are valence limited. Prototypical examples are networks of patchy particles, where the limited valence results from highly directional pairwise interactions. We combine extensive Langevin simulations and Wertheim’s theory of association to study these networks. We find a scale-free (relaxation) dynamics within the liquid–gas coexistence region, which differs from that usually observed for isotropic particles. While for isotropic particles the relaxation dynamics is driven by surface tension (coarsening), in low-density networks the slow relaxation proceeds through the formation of an intermediate non-equilibrium gel via a geometrical percolation transition. We show that the low temperature slow dynamics is universal, being observed also in the single phase region.

C. S. Dias, J. M. Tavares, N. A. M. Araujo and M. M. Telo da Gama, Soft Matter 14, 2744 (2018).