title: Patterned layers of a semiconducting polymer via imprinting and microwave-assisted grafting.
abstract: Enhancements in both the rate and extent of grafting of poly(9,9'-n-dihexyl fluorene) (PDHF) onto flat and nanopatterned crosslinked photopolymer films are described. Reactivity of the surfaces toward grafting via the Yamamoto-type Ni(0)-mediated coupling reaction is increased by synthesizing and incorporating 2,7-dibromo-9-fluorenyl methacrylate (DBFM, 2) as a new grafting agent. Varying the concentration of surface-embedded DBFM is shown to control both overall graft formation and fluorescence with a maximum thickness of up to 30 nm and peak emission at 407 nm for 40 wt% loading. In addition, microwave irradiation is introduced as an effective means to drive graft formation and thus allows fabrication of PDHF-functionalized surfaces in as little as 30 min. Both forms of improvement are extended to DBFM-embedded, nanocontact-molded features ranging in size from 100 microm to 100 nm in width and 60 nm in height. Microwave-assisted grafting from these patterned surfaces produces fluorescent features as imaged by optical microscopy and a corresponding increase in feature height as measured by atomic force microscopy.
authors.affiliation: Department of Polymer Science and Engineering, University of Massachusetts, Amherst Conte Center for Polymer Research, 120 Governors Drive, Amherst, MA 01003, USA.
authors.forename: Isaac W
authors.initials: IW
authors.lastname: Moran
authors.forename: Sarav B
authors.initials: SB
authors.lastname: Jhaveri
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Carter
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D005449:Fluorenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry; D008872:Microwaves; D010781:Photography; D011108:Polymers / Q000737:chemistry*; D011327:Printing; D012666:Semiconductors
chemical_list: D001672:Biocompatible Materials; D005449:Fluorenes; D008689:Methacrylates; D011108:Polymers