oa Temperature Dependent Heat Transfer Performance of Multi-walled Carbon Nanotube-based Aqueous Nanofluids at Very Low Particle Loadings

Aqueous suspensions of multi-walled carbon nanotubes (MWCNTs + deionised water) have been synthesised. Carbon nanotubes (CNTs) were derived by chemical vapour deposition (CVD). Transmission electron microscopy (TEM) measurements show the formation of MWCNTs. Three samples of CNT-based aqueous nanofluids having MWCNT concentrations of 0.01 vol%, 0.03 vol% and 0.05 vol% were prepared with the help of ultrasonic irradiation. A very small amount of sodium dodecyl sulfate (SDS) was used as a surfactant to minimise the agglomeration of the MWCNTs. An effective enhancement in thermal conductivity was observed at different temperatures. The obtained results are explained with percolation theory.