title: Thermoreversible Morphology and Conductivity of a Conjugated Polymer Network Embedded in Block Copolymer Self-Assemblies.
abstract: Self-assembly of block copolymers provides numerous opportunities to create functional materials, utilizing self-assembled microdomains with a variety of morphology and periodic architectures as templates for functional nanofillers. Here new progress is reported toward the fabrication of thermally responsive and electrically conductive polymeric self-assemblies made from a water-soluble poly(thiophene) derivative with short poly(ethylene oxide) side chains and Pluronic L62 block copolymer solution in water. The structural and electrical properties of conjugated polymer-embedded self-assembled architectures are investigated by combining small-angle neutron and X-ray scattering, coarse-grained molecular dynamics simulations, and impedance spectroscopy. The L62 solution template organizes the conjugated polymers by stably incorporating them into the hydrophilic domains thus inhibiting aggregation. The changing morphology of L62 during the micellar-to-lamellar phase transition defines the embedded conjugated polymer network. As a result, the conductivity is strongly coupled to the structural change of the templating L62 phase and exhibits thermally reversible behavior with no signs of quenching of the conductivity at high temperature. This study shows promise for enabling more flexibility in processing and utilizing water-soluble conjugated polymers in aqueous solutions for self-assembly based fabrication of stimuli-responsive nanostructures and sensory materials.
authors.affiliation: Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Han
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.|Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Jan-Michael Y
authors.initials: JY
authors.lastname: Carrillo
authors.affiliation: Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.|Forschungszentrum Jülich, Jülich Center for Neutron Science, Jülich, NRW, 52425, Germany.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Li
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Kunlun
authors.initials: K
authors.lastname: Hong
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.|Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Sumpter
authors.affiliation: Forschungszentrum Jülich, Jülich Center for Neutron Science, Jülich, NRW, 52425, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Ohl
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Mariappan Parans
authors.initials: MP
authors.lastname: Paranthaman
authors.affiliation: Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Smith
authors.affiliation: Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. doc1@ornl.gov.
authors.forename: Changwoo
authors.initials: C
authors.lastname: Do
mesh_terms: D058266:Dielectric Spectroscopy; D004553:Electric Conductivity; D056004:Molecular Dynamics Simulation; D033363:Neutron Diffraction; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D053838:Scattering, Small Angle; D012996:Solutions; D013696:Temperature; D013876:Thiophenes / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D011108:Polymers; D012996:Solutions; D013876:Thiophenes; C066730:polythiophene; D011092:Polyethylene Glycols
keywords: conjugated polymers; self-assembly; small-angle scattering; thermoreversible conductivity; triblock copolymers