Experimental investigation of thermal and electrical conductivity of silicon oxide nanofluids in ethylene glycol/water mixture

• Published in: International journal of heat and mass transfer Vol. 117; pp. 280 - 286
• Main Authors: Guo, Yufeng, Zhang, Tongtong, Zhang, Dongrui, Wang, Qi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2018; Elsevier BV
• Subjects: Antifreeze solutions; Conductivity; Electrical conduction mechanism; Electrical conductivity; Electrical resistivity; Ethylene glycol; Heat transfer; Nanofluids; Nanoparticles; Silicon dioxide; Silicon oxides; SiO2 nanofluids; Thermal conductivity; Thermo-electrical conductivity ratio; Viscosity; Thermal conductivity; Thermo-electrical conductivity ratio; Electrical conductivity; Electrical conduction mechanism; SiO2 nanofluids
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2017.09.091

•Thermal and electrical conductivity of SiO2 based-nanofluids were studied.•Ethylene glycol content dominates conductivity, rather than temperature.•Ionic adsorption capacity of nanoparticles enhances the electrical conductivity.•Temperature can impact the electrical conductivity through electric double layer. In this paper, the thermal conductivity and electrical conductivity of SiO2 nanofluids using mixture of ethylene glycol (EG) and water (H2O) as the base fluid are investigated. The two-step method was used to prepare SiO2-EG/H2O nanofluids with a mass concentration of 0.3%. The variations in thermal conductivity and electrical conductivity as functions of EG concentration (0–100%, v/v) and temperature (25–45 °C) are present. Experimental results showed that the thermal conductivity and electrical conductivity of SiO2-EG/H2O nanofluids both decreased as the EG content percentage increases in the EG/H2O mixture. At a specific EG content percentage, thermal conductivity and electrical conductivity both increased with the increase in temperature. To better evaluate the enhancement performance of SiO2-EG/H2O nanofluids, the relative electrical conductivity was introduced and studied explicitly. The mechanism of electrical conductivity enhancement in SiO2-EG/H2O nanofluids was analyzed in detail. Meanwhile, the ratio of thermal conductivity and electrical conductivity was also discussed.