Reversible temperature regulation of electrical and thermal conductivity using liquid-solid phase transitions

Nat Commun. 2011;2:289. doi: 10.1038/ncomms1288.

Abstract

Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce a general strategy to achieve large contrasts in electrical and thermal conductivities using first-order phase transitions in percolated composite materials. Internal stress generated during a phase transition modulates the electrical and thermal contact resistances, leading to large contrasts in the electrical and thermal conductivities at the phase transition temperature. With graphite/hexadecane suspensions, the electrical conductivity changes 2 orders of magnitude and the thermal conductivity varies up to 3.2 times near 18 °C. The generality of the approach is also demonstrated in other materials such as graphite/water and carbon nanotube/hexadecane suspensions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alkanes / chemistry
  • Electric Conductivity*
  • Graphite / chemistry
  • Microscopy, Electron, Transmission
  • Models, Theoretical*
  • Nanotubes / chemistry
  • Nanotubes / ultrastructure
  • Phase Transition*
  • Temperature*
  • Thermal Conductivity*
  • Ultrasonics

Substances

  • Alkanes
  • Graphite
  • n-hexadecane