We utilize chemically patterned substrates with arrays of progressively narrower stripes (1-15 mm) to investigate the influence of pattern size on the morphology of dewetting polystyrene films. The early-stage dewetting patterns align with the substrate patterns, leading to the formation of correlated droplet arrays. The droplets become anisotropic after they coarsen to a scale comparable to the stripe width, and then undergo a morphological transition to circular shaped droplets that cross multiple stripes. This leads to quantization of droplet size and contact-angle.
Citation: Physical Review Letters
Pub Type: Journals
anisotropic spinodal dewetting, atomic force microscopy, contact angles, high-throughput, morphological transitions, polymer thin-films, self-assembled monolayers