Organized structures in diblock copolymer films of polystyrene and poly-para-methylstyrene.

A diblock copolymer of poly(styrene-block-para-emthylstyrene) (PS-b-PMS) is investigated near its microphase separation temperature with respect to the formation of organized structures in thin films. A contract between components is achieved by deuteration of the PS-block, and the surface-induced order is detected by neutron reflectometry and 15N nuclear reaction analysis. While the PMS component is always enriched at the surface, an exponentially decaying lamellar order of alternating layers of PS and PMS parallel to the surface is observed depending on annealing time. Those observations are discussed with respect to the influence of surface and substrate on the development of organized structures in a block copolymer melt. [ABSTRACT FROM AUTHOR]