Spinodal Dewetting on Chemically Patterned Substrates
A Sehgal, V Ferreiro, Jack F. Douglas, Eric J. Amis, Alamgir Karim
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.