(494e) Droplet Formation in Elastic Polymer Networks

Stable droplets formed via liquid-liquid phase separation have been observed in both biological and synthetic elastic matrix. Here, we study the thermodynamics of droplet formation inside polymer networks through combining the classical nucleation theory and network elasticity. We predict that droplets can be stable under certain conditions and show that the stability of droplets is determined by the competition between the solvation energy which favors phase separation and the elastic energy as the restraining force. The network stiffness significantly affects droplet size, nucleation energy barrier and critical nuclei size. By incorporating strand breakage effects, we are able to predict micrometer-sized droplets observed in experiments, and the predictions are in quantitative agreement with experimental results. Further, we provide an energy perspective on the elastic ripening process driven by network stiffness gradients.