Viscosity and thermal conductivity of dispersions of gum arabic capped MWCNT in water: Influence of MWCNT concentration and temperature

Experiments were carried out on the measurement of viscosity and thermal conductivity of multi-walled carbon nanotubes (MWCNT)-water nanofluids prepared using gum arabic as dispersant. The influence of temperature (28–60 °C), MWCNT concentration (0.14–0.24 vol%) on viscosity and effective thermal conductivity has been investigated. Our results on the effect of MWCNT concentration on relative viscosity and thermal conductivity ratio are in qualitative agreement with those reported in literature. Thermal conductivity ratios increase strongly with temperature, especially above 45 °C. Relative viscosities too increased with temperature above 45 °C at relatively higher MWCNT concentration indicating the potential role of Brownian motion.

► MWCNT shortened by ultrasonication; dispersed in water using gum arabic. ► Nanofluid thermal conductivity and viscosity measured up to a temperature of 60 °C. ► Role of Brownian motion confirmed in viscosity & thermal conductivity enhancement.