Kinetics of Individual Block Copolymer Island Formation and Disappearance near an Absorbing Boundary

We investigate the formation and coalescence of surface relief structures in symmetric diblock copolymers films of poly(styrene- b -2-vinylpyridine) (PS−PVP) on chemically patterned surfaces. The substrates have patterns of self-assembled monolayers (SAMs) produced by microcontact printing HO-terminated (HO−) SAM stripes alternating with H 3 C-terminated (H 3 C−) SAM stripes. The PS−PVP lamellae over the H 3 C−SAM have a defect-rich morphology compared to the film above the HO−SAM. These film sections above the H 3 C−SAM attract excess PS−PVP that would normally form islands on a uniform substrate. In the early stages of annealing waves of thickness develop from the H 3 C/HO−SAM boundary and propagate into the film over the HO−SAM. For a 3 μm wide HO−SAM stripe a single line of excess copolymer breaks up into a single line of islands with a well-defined spacing along the grating. At long times these islands dissolve by transport of copolymer to the H 3 C−SAM stripe. The well-defined 2D geometry allows us to analyze the transport leading to this dissolution quantitatively. The rate-controlling process during the island dissolution is two-dimensional pressure relaxation.