Mechanisms of ordering in striped patterns

We have studied the ordering dynamics of the striped patterns of a single l ayer of cylindrical block copolymer microdomains in a thin film. By trackin g disclinations during annealing with time-lapse atomic force microscopy, w e observe a dominant mechanism of disclination annihilation involving three or four disclinations (quadrupoles). Pairwise disclination annihilation ev ents are suppressed as a result of the topological constraints in this syst em. The kinetic scaling laws with exponents observed here are consistent wi th topologically allowed annihilation events involving multiple disclinatio ns. The results provide insight into two-dimensional pattern formation and may lead to the successful application of block copolymer lithography.