• DOI:10.1021/nl4007326
• Corpus ID: 13078661

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

@article{Losego2013UltralowTC,
  title={Ultralow thermal conductivity in organoclay nanolaminates synthesized via simple self-assembly.},
  author={Mark D. Losego and Ian P. Blitz and Richard A. Vaia and David G. Cahill and Paul V. Braun},
  journal={Nano letters},
  year={2013},
  volume={13 5},
  pages={
          2215-9
        }
}

• M. Losego, I. P. Blitz, +2 authors P. Braun
• Published 18 April 2013
• Materials Science
• Nano letters

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.