title: High thermal conductivity of chain-oriented amorphous polythiophene.
abstract: Polymers are usually considered thermal insulators, because the amorphous arrangement of the molecular chains reduces the mean free path of heat-conducting phonons. The most common method to increase thermal conductivity is to draw polymeric fibres, which increases chain alignment and crystallinity, but creates a material that currently has limited thermal applications. Here we show that pure polythiophene nanofibres can have a thermal conductivity up to ∼ 4.4 W m(-1) K(-1) (more than 20 times higher than the bulk polymer value) while remaining amorphous. This enhancement results from significant molecular chain orientation along the fibre axis that is obtained during electropolymerization using nanoscale templates. Thermal conductivity data suggest that, unlike in drawn crystalline fibres, in our fibres the dominant phonon-scattering process at room temperature is still related to structural disorder. Using vertically aligned arrays of nanofibres, we demonstrate effective heat transfer at critical contacts in electronic devices operating under high-power conditions at 200 °C over numerous cycles.
authors.affiliation: 1] George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332, USA [2].
authors.forename: Virendra
authors.initials: V
authors.lastname: Singh
authors.affiliation: 1] George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332, USA [2].
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Bougher
authors.affiliation: Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Annie
authors.initials: A
authors.lastname: Weathers
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, J. Erskine Love Building, Atlanta, Georgia 30332, USA.
authors.forename: Ye
authors.initials: Y
authors.lastname: Cai
authors.affiliation: 1] Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, Texas 78712, USA [2] School of Mechanical Engineering, Southeast University, Nanjing, 211189, China.
authors.forename: Kedong
authors.initials: K
authors.lastname: Bi
authors.affiliation: Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Pettes
authors.affiliation: Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Sally A
authors.initials: SA
authors.lastname: McMenamin
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Lv
authors.affiliation: Raytheon Company, Sudbury, Massachusetts 01776, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Resler
authors.affiliation: Raytheon Company, Sudbury, Massachusetts 01776, USA.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Gattuso
authors.affiliation: Raytheon Company, Sudbury, Massachusetts 01776, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Altman
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, J. Erskine Love Building, Atlanta, Georgia 30332, USA.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Sandhage
authors.affiliation: Department of Mechanical Engineering, The University of Texas at Austin, 204 East Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Shi
authors.affiliation: 1] George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332, USA [2] School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, J. Erskine Love Building, Atlanta, Georgia 30332, USA.
authors.forename: Asegun
authors.initials: A
authors.lastname: Henry
authors.affiliation: 1] George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332, USA [2] School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, J. Erskine Love Building, Atlanta, Georgia 30332, USA.
authors.forename: Baratunde A
authors.initials: BA
authors.lastname: Cola