Transition Behavior in Silicone-coated Sand Mixtures

Granular media with a small amount of liquid possess a significant stiffness caused by interactions or capillary bridges compared to the same system when dry. Recently, another type of interacting sand where each grain is coated by silicone-oil is produced. However, macroscopic physical properties of such systems are not yet understood. In this work, we mixed the silicone-coated sand to uncoated one, and examined the static properties of the interacting composite granular system with three independent experiments. We then observed a characteristic transition of macroscopic behaviors by changing the fraction of coated sand. This work can advance our fundamental understandings of interacting granular systems.