Carbon nanotubes suspended in ethylene glycol yield nanofluids with enhanced heat transfer properties

Abstract

Nanofluids (NFs) consisting of carbon nanotubes (CNTs) suspended in ethylene glycol (EG) were synthesized, and their stability and thermal conductivity enhancement rate were investigated. Stability of the CNT/EG-based NFs was enhanced by adding gum Arabic (GA). The increase in suspension stability was experimentally characterized using static and centrifugal testing processes. The mechanisms of GA in enhancing the fluid stability were characterized and the optimal mass ratio of GA to CNT was found to be about 11% by weight. Thermal conductivity was measured for varying CNT volume fraction under different fluid temperatures, and a nearly linear relationship between the thermal conductivity and the CNT volume fraction and temperature was observed.