Ultralow thermal conductivity in organoclay nanolaminates synthesized via simple self-assembly

Mark D. Losego, Ian P. Blitz, Richard A. Vaia, David G. Cahill, Paul V. Braun

Research output: Contribution to journalArticle

Abstract

Because interfaces impede phonon transport of thermal energy, nanostructuring can transform fully dense solids into ultralow thermal conductivity materials. Here we report a simple self-assembly approach to synthesizing organoclay nanolaminates with cross-planar thermal conductivities below 0.10 W m-1 K-1 - a 5-fold decrease compared to unmodified clay. These organoclays are produced via alkylammonium cation exchange with colloidally dispersed montmorillonite clay sheets followed by solvent casting. Time-domain thermoreflectance (TDTR) is used to evaluate the thermal conductivity of the organoclay nanolaminates. Variations in both organic layer thickness and cation chemistry are investigated. At these interface densities (1.0-1.5 interfaces/nm), we demonstrate that thermal conductivity is relatively independent of nanolaminate spacing. A simple series resistance model describes the behavior and gives an interfacial thermal conductance value of ≈150 MW m-2 K-1 for the organic/clay interface, consistent with similar organic-inorganic interfaces. The wide range of compositional substitutions and structural variations possible in these materials, make organoclays a versatile new platform for investigating the underlying physics of nanolaminate structures.

Original languageEnglish (US)
Pages (from-to)2215-2219
Number of pages5
JournalNano letters
Volume13
Issue number5
DOIs
StatePublished - May 8 2013

Keywords

  • interfacial thermal conductance
  • nanolaminate
  • organoclay
  • self-assembly
  • Thermal conductivity

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Ultralow thermal conductivity in organoclay nanolaminates synthesized via simple self-assembly'. Together they form a unique fingerprint.

  • Cite this