title: Formation and Reversible Morphological Transition of Bicontinuous Nanospheres and Toroidal Micelles by the Self-Assembly of a Crystalline-b-Coil Diblock Copolymer.
abstract: We herein report the formation of two complex nanostructures, toroidal micelles and bicontinuous nanospheres, by the self-assembly of the single structurally simple crystalline-b-coil diblock copolymer poly[bis(trifluoroethoxy)phosphazene]-b-poly(styrene), PTFEP-b-PS, in one solvent (THF) and without additives. The nature of these nanostructures in solution was confirmed by DLS and cryo-TEM experiments. The two morphologies are related by means of a new type of reversible morphological evolution, bicontinuous-to-toroidal, triggered by changes in the polymer concentration. WAXS experiments showed that the degree of crystallinity of the PTFEP chains located at the core of the toroids was higher than that in the bicontinuous nanospheres, thus indicating that the final morphology of the aggregates is mostly determined by the ordering of the PTFEP core-forming blocks.
authors.affiliation: Facultad de Química, Química Orgánica e Inorgánica (IUQOEM), Universidad de Oviedo, Julián Clavería s/n, 33006, Oviedo, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Presa-Soto
authors.affiliation: Facultad de Química, Química Orgánica e Inorgánica (IUQOEM), Universidad de Oviedo, Julián Clavería s/n, 33006, Oviedo, Spain.
authors.forename: Gabino A
authors.initials: GA
authors.lastname: Carriedo
authors.affiliation: Facultad de Química, Química Orgánica e Inorgánica (IUQOEM), Universidad de Oviedo, Julián Clavería s/n, 33006, Oviedo, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: de la Campa
authors.affiliation: Facultad de Química, Química Orgánica e Inorgánica (IUQOEM), Universidad de Oviedo, Julián Clavería s/n, 33006, Oviedo, Spain. presaalejandro@uniovi.es.
authors.forename: Alejandro
authors.identifier: 0000-0003-3565-4672
authors.initials: A
authors.lastname: Presa Soto
keywords: bicontinuous nanospheres; block copolymers; polyphoshazenes; self-assembly; toroidal micelles