Investigation on the Electrical Conductivity of Aqueous Glycol based ZnO Nanofluids

Nanotechnology research has proved sustainable results for a wide range of applications from engineering to medical science. Nanotechnology corresponds to the engineering of materials in nanosize (۱۰-۹m) whose material properties differ from of bulk properties. Nanofluid is one category of applications reported for its use as thermal management in cooling of electronic devices and fuel cell applications. In most literature, electrical conductivity studies were used as a basis to define the stability of nano-suspensions. In the present paper, the electrical conductivity studies of two glycol based nanofluids dispersed with ZnO nanoparticles of ۵۰nm average diameter in the temperature range of ۳۰-۵۵۰C are reported. ZnO nanoparticles are added to the aqueous glycol base fluid prepared with (۳۰ EG: ۷۰ Water) and (۳۰ PG: ۷۰ Water) composition at a low volume concentration of ۰.۰۱ to ۰.۰۵%. Correlations are developed using experimental results for each volume concentration to predict electrical conductivity (EC) of nanofluids with temperature. From obtained results, the electrical conductivity of aqueous propylene glycol shows a decrement in EC after adding ZnO nanoparticles (except at ۰.۰۴% volume concentration) and vice versa for aqueous ethylene glycol. For aqueous propylene and ethylene glycol nanofluids, electrical conductivity enhancement up to ۲۰% and ۱۲% is obtained at a volume concentration of ۰.۰۴% and ۰.۰۱% at ۵۵۰C temperature respectively. The electrical conductivity of both nanofluids increases with increase in temperature at all volume concentrations.

Keywords:

Electrical conductivity , ZnO , Aqueous glycol , Nanofluids , Ion condensation effect , Volume concentration , Temperature