Coarsening dynamics of networks of binary DNA droplet chains

Predicting the time evolution of geometries formed during multiphase liquid-liquid phase separation is a challenge for statistical physics, intracellular organization and materials design. While the mechanisms underlying individual droplet structures have been intensively investigated, mechanistic analyses of larger-scale mesoscopic patterning remain limited. In this study, we use a DNA nanoparticle platform with tunable interparticle attractions to create a quasi-two-dimensional network of chains of DNA droplets, with each chain composed of two alternating, immiscible droplet phases. The network coarsens with time, with both the mesh size and the average droplet radius exhibiting a power-law growth that is independent of droplet adhesion strength and particle binding energy. Coarsening is driven by droplet collision-coalescence processes that only occur in the vicinity of network junctions. We show that the measured growth exponents can be understood based on the self-similar growth of both the droplet size distribution and the network geometry. Our results describe a new class of pattern formation dynamics in multicomponent phase-separating systems and suggest a means to control mesoscopic droplet organization.