title: The Self-Assembled Structure of the Diblock Copolymer PCL-b-P4VP Transforms Upon Competitive Interactions with Octaphenol Polyhedral Oligomeric Silsesquioxane.
abstract: This paper describes the miscibility and self-assembly, mediated by hydrogen-bonding interactions, of new block copolymer/nanoparticle blends. The morphologies adopted by the immiscible poly[(ε-caprolactone)-block-(4-vinyl pyridine)] (PCL-b-P4VP) diblock copolymer changes upon increasing the number of competitive hydrogen-bonding interactions after adding increasing amounts of octaphenol polyhedral oligomeric silsesquioxane (OP-POSS). Transmission electron microscopy reveals morphologies that exhibit high degrees of long-range order, such as cylindrical and spherical structures, at relatively low OP-POSS contents, and short-range order or disordered structures at higher OP-POSS contents. Analyses performed using differential scanning calorimetry, wide-angle X-ray diffraction, and FT-IR spectroscopy provide positive evidence that the pyridyl units of the P4VP block are significantly stronger hydrogen-bond acceptors toward the OH group of OP-POSS than are the CO groups of the PCL block, thereby resulting in excluded and confined PCL phases.
authors.affiliation: Institute of Applied Chemistry, National Chiao-Tung University, Hsin-Chu, Taiwan (ROC).
authors.forename: Chu-Hua
authors.initials: CH
authors.lastname: Lu
authors.forename: Shiao-Wei
authors.initials: SW
authors.lastname: Kuo
authors.forename: Wen-Teng
authors.initials: WT
authors.lastname: Chang
authors.forename: Feng-Chih
authors.initials: FC
authors.lastname: Chang