Order-disorder transition in surface-induced nanopattern of diblock copolymer films

Formation of surface-induced nanopattern (SINPAT) in ultrathin diblock copo lymer films is studied by scanning force microscopy and Monte Carlo simulat ion. The pattern is caused by strong adsorption of one of the two blocks fo rming a quasi-two-dimensional coil while the other block dewets this adsorp tion layer. Scanning force microscopy allowed to observe an order-disorder transition for a SINPAT film of polystyrene-block-poly(2-vinylpyridine) on mica when the length of the dewetting polystyrene block was varied. The exp erimental data are compared with the Monte Carlo simulations which demonstr ate how the pattern formation depends on the degree of polymerization of th e dewetting block and the unfavorable interaction potential between the dif ferent components.