Thermal conductivity of suspensions of carbon nanotubes in water

The enhancement of the thermal conductivity of water in the presence of carbon-multiwall nanotubes (C-MWNT) was investigated. Sodium dodecyl sulfate (SDS) was employed as the dispersant, and a 0.6 vol% suspension of C-MWNT in water was used in all measurements. The thermal conductivity was measured with a transient hot-wire instrument built for this purpose, and operated with a standard uncertainty better than 2%. The maximum thermal conductivity enhancement obtained was 38%. In an attempt to explain the experimental observations, a number of micro-structural investigations have been carried out and those results are presented here along with the analysis.