Atomic force microscopy study of comb-like vs. arborescent graft copolymers in thin films

This work deals with the study of comb-like vs. arborescent grafted copolymers made of poly(chloroethyl vinyl ether)-g-polystyrene (PCEVE-g-PS). We describe how the molecular architecture of the branched polymers affects their nanoscale organization in thin films, as observed using atomic force microscopy. The results indicate that modifying the molecular architecture from a 'generation-zero' comb-like (PCEVE-g-PS) to a 'first-generation' hyperbranched (PCEVE-g-(PS-b-PCEVE-g-PS)) architecture strongly modifies the observed geometrical parameters of the molecules, in good agreement with the expected evolution of the molecular dimensions and the corresponding data obtained in solution. The surface organization of the (PCEVE-g-PS) copolymer molecules is also strongly conditioned by the interplay between the molecule-substrate interactions and the molecule-molecule interactions, leading to different possible orientations of the lateral branches with respect to the surface and thus to different final morphologies. (C) 2004 Elsevier Ltd. All rights reserved.