Interfacial thermal conductance in spun-cast polymer films and polymer brushes

Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA
Applied Physics Letters (Impact Factor: 3.3). 08/2010; 97(1):011908 - 011908-3. DOI: 10.1063/1.3458802
Source: IEEE Xplore


Interfaces between inorganic materials and anharmonic polymers have potentially intriguing thermal transport behavior. The low thermal conductivity of amorphous polymers limits significant interfacial effects to polymer film thicknesses of only a few nanometers. We use time-domain thermoreflectance to directly measure interfacial effects in the thermal conductance of spun-cast poly(methyl methacrylate) (PMMA) thin films and PMMA brushes “grafted-from” the substrate. PMMA brushes are expected to have polymer chains partially aligned perpendicular to the substrate, yet only a modest increase (13%) in thermal conductivity is observed over spun-cast layers.

Download full-text


Available from: David G Cahill, Jan 06, 2015
1 Follower
31 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Heat can tunnel across a vacuum gap due to near-field electromagnetic effects. The effect is a result of image potential theory, and heat transfer falls off roughly as the inverse of the gap distance. This effect is in addition to the transfer of heat by photons. This phenomena has been observed previously in scanning tunneling microscopy.
    Applied Physics Letters 03/2011; 98(13). DOI:10.1063/1.3573800 · 3.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Generally polymer bulk structures and nanostructures are thermally insulative. In this study, we show that an improved nanoporous template wetting technique can prepare thermally conductive polymer nanowire arrays. The thermal conductivities of the fabricated high-density polyethylene (HDPE) nanowire arrays with diameters of 100 nm and 200 nm, measured by a laser flash method, are about 2 orders of magnitude higher than their bulk counterparts. The estimated thermal conductivity of a single HDPE nanowire is as high as 26.5 W/mK at room temperature. The high orientation of chains of the HDPE nanowires may arise from the integrative effects of shear rate, vibrational perturbation, translocation, nanoconfinement and crystallization. Findings in this study provide useful strategies on enhancing the intrinsic thermal properties of polymer nanostructures.
    Polymer 04/2011; 52(8):1711-1715. DOI:10.1016/j.polymer.2011.02.019 · 3.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pressure dependence of thermal conductivity provides a critical test of the validity of the model of the minimum thermal conductivity for describing heat transport by molecular vibrations of an amorphous polymer. We measure the pressure dependence of the thermal conductivity (P) of poly(methyl methacrylate) using a combination of time-domain thermoreflectance and SiC anvil-cell techniques. We also determine (P) from a computational model of amorphous polystyrene. In both cases, (P) is accurately predicted by the minimum thermal conductivity model via the pressure dependence of the elastic constants and density.
    Physical review. B, Condensed matter 05/2011; 60(17). DOI:10.1103/PhysRevB.83.174205 · 3.66 Impact Factor
Show more