Investigation on stability of tri-hybrid nanofluids in water-ethylene glycol mixture

摘要

Nanofluid is a suspension of liquid containing metal or non-metallic nanoparticles of typical size(1-100 nm)dispersed into the base liquid.Hybrid or composite nanofluids is considered an extension of research work for single nanofluids,which can be carried out through a combination of two or more different nanoparticles-either in mixed or dispersed composites in liquids.The objective of this study is to investigate the stability of tri-hybrid nanofluids suspended in Water-Ethylene Glycol(EG)mixture.The tri-hybird nanofluids were prepared at a volume concentration of 0.05 to 0,3% using the two-step method.Three types of nanoparticles used namely Al2O3,TiO2 and SiO2,and dispersed in a base fluid of water/EG.The investigation on the stability of the hybrid nanofluids in the present study is conducted through UV-Vis,zeta-potential,sedimentation and micrograph observation.The findings from the investigations on the visual stability of sedimentation show that the differences in concentration(0.05,0.1,0.2,0.3%)have been low in day 14.It was found that 10 h sonication time is the most suitable period for sonication to obtain a stable suspension.Comparison of data concentration ratio to sedimentation for single,hybrid and tri-hybrid nanofluids presents tri-hybrid nanofluids remains stable with a concentration ratio of 80%.Zeta potential evaluation conducted for the tri-hybrid nanofluids obtained the value of 25.1 mV in the classification of good stability.It can be concluded that the tri-hybrid nanofluids were successfully prepared and achieved good stability.