WETTING BEHAVIOR OF HOMOPOLYMER FILMS ON CHEMICALLY SIMILAR BLOCK-COPOLYMER SURFACES

The wetting properties of thin polystyrene (PS) homopolymer films (pol ymerization index N(H)) were studied on the surfaces of polyvinylpyrid ine-polystyrene (PVP-PS) block copolymer films (polymerization indices N(PS) and N(PVP)) oriented into lamellae with the PS block present at the vacuum interface. Autodewetting was observed on the diblock copol ymer surface when N(H)/N(PS) greater-than-or-equal-to 5, with a contac t angle independent of N(H), but decreasing with N. The dewetting nucl eated at the base of islands on the ordered PVP-PS surfaces. The dewet ting processes were explained using mean field theories and Monte Carl o simulations.