Fig. 2: Schematic illustration of droplet instability due to Ostwald ripening and coalescence.

a Ostwald ripening: Large droplets grow at the expense of small unstable droplets. Over time, larger ripened droplets with reduced surface tension and area are observed. b Coalescence: Small droplets coalesce to minimize the surface tension. Over time, coalesced large droplets in a comparatively stable conformation with reduced surface tension and surface area are formed.