title: Air-liquid interfacial self-assembly of conjugated block copolymers into ordered nanowire arrays.
abstract: The ability to control the molecular packing and nanoscale morphology of conjugated polymers is important for many of their applications. Here, we report the fabrication of well-ordered nanoarrays of conjugated polymers, based on the self-assembly of conjugated block copolymers at the air-liquid interface. We demonstrate that the self-assembly of poly(3-hexylthiophene)-block-poly(ethylene glycol) (P3HT-b-PEG) at the air-water interface leads to large-area free-standing films of well-aligned P3HT nanowires. Block copolymers with high P3HT contents (82-91%) formed well-ordered nanoarrays at the interface. The fluidic nature of the interface, block copolymer architecture, and rigid nature of P3HT were necessary for the formation of well-ordered nanostructures. The free-standing films formed at the interface can be readily transferred to arbitrary solid substrates. The P3HT-b-PEG films are integrated in field-effect transistors and show orders of magnitude higher charge carrier mobility than spin-cast films, demonstrating that the air-liquid interfacial self-assembly is an effective thin film fabrication tool for conjugated block copolymers.
authors.affiliation: Departments of Chemistry, ‡Materials Science and Engineering, §Chemical and Biomolecular Engineering, and ∥Electrical and Systems Engineering, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ma Helen M
authors.initials: MH
authors.lastname: Cativo
authors.forename: David K
authors.initials: DK
authors.lastname: Kim
authors.forename: Robert A
authors.initials: RA
authors.lastname: Riggleman
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Yager
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Nonnenmann
authors.forename: Huikuan
authors.initials: H
authors.lastname: Chao
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Bonnell
authors.forename: Charles T
authors.initials: CT
authors.lastname: Black
authors.forename: Cherie R
authors.initials: CR
authors.lastname: Kagan
authors.forename: So-Jung
authors.initials: SJ
authors.lastname: Park
keywords: air−water interface; amphiphilic polymer; conjugated copolymer; self-assembly; supramolecular chemistry