Impact dynamics of droplets with silicananoparticles and polymer additives

We investigate the impact dynamics of droplets containing silica nanoparticles and/or poly(ethylene oxide) (PEO) additives by using a high speed camera, and relate the impact behavior to the rheological properties of liquids. For a droplet with both particles and polymer additives, the rebound is damped much faster and the instability behavior is suppressed. Interestingly, the rebound can be inhibited even when impact is at high velocity (1.88 m s−1). The transition from “rebound” to “stick” by enhancing the impact velocity is mainly due to the increase of the friction force of the nanoparticles and polymer aggregates with the substrate. This is confirmed by the increase of the sliding angle with impact velocity.