On the use of glycosylated single-walled carbon nanotubes as a coolant additive

A dispersion of single-walled carbon nanotubes (SWCNTs) in an aqueous medium was prepared by functionalizing the SWCNT with D-glucosamine, as confirmed using FT-IR and NMR techniques. The SWCNT and sugar functionalized SWCNT were studied using scanning and transmission electron microscopy. The grafting resulted in a good dispersion of the SWCNTs in water of an amount less than 1 mg ml-1. The thermal conductivity was measured using high sensitivity thermistor, whose resistance was measured using a 6½ digit multimeter. Assuming the Fourier heat conduction equation to be valid for an analysis of the present situation (to determine the overall heat transfer coefficient), a 24% increase in the rate of heat transfer was arrived at for dispersions of less than 0.1% sugar functionalized SWCNTs in 1 ml of water. These results are compared with results on SWCNT and MWCNT dispersions in various media in order to demonstrate the superior heat transfer properties of the present medium