A study on the characteristics of carbon nanofluids at the room temperature (25°C)

The proper mixture ratio of nanofluids was examined by measuring thermal conductivity via transient hot-wire method. Comparisons are made with the nanofluid prepared by dispersing oxidized Multi-Walled Carbon NanoTubes (MWCNTs) in distilled water (herein referred to as oxidized nanofluid). Viscosity measurements were also carried out for the PVP-added nanofluids and oxidized nanofluids by using a digital viscometer. The nanofluids with 300 wt.% PVP and oxidized MWCNTs exhibited better thermal conductivity than that reported in previous studies. The thermal conductivity of oxidized carbon nanofluids was the highest of those compared and the use of additives in the nanofluid preparation deems to increase viscosity. For industrial applications, the chemical dispersion method applied in the preparation of oxidized carbon nanofluids should be considered as it offers high thermal conductivity with a slight increase in viscosity. (C) 2010 Elsevier Ltd. All rights reserved.