Thermophysical properties of ethylene glycol mixture based CNT nanofluids

Nanofluids are produced by dispersing nanometer-scale solid particles into base liquids such as water, ethylene glycol, etc. The thermal quadrupole method is utilized to determine the thermophysical properties of materials. By this technique, the thermal diffusivity and conductivity of different nanofluids containing surfactants (humic acid, sodium salt of humic acid and sodium carboxymethyl cellulose and multi-wall carbon nanotubes were evaluated at room temperature and at 75 degrees C. Values of thermal diffusivity varying in the range from 9.60x10(-8) m(2)s(-1) to 1.46x10(-7) m(2)s(-1) and thermal conductivity from 0.26 Wm(-1)K(-1) to 0.41 Wm(-1)K(-1) were obtained. As main conclusions, it was noted that nanofluids exhibit superior heat transfer characteristics than the conventional heat transfer fluid and the thermal conductivity is enhanced by 50 % for the nanofluid containing 0.0275 mg/mL of sodium salt of humic acid + ethylene glycol, at the temperature of 25 degrees C.