Effect of Exfoliated Graphene on Thermal Conductivity Enhancements of Graphene-Ironoxide Hybrid Nanofluids: Experimental Investigation and Effective Medium Theories

Reasoning of particular mechanism anomalous thermal transport behaviours are not identified yet for the nanofluids. In this study, iron oxide (Maghemite: MH) and graphene (Gr) flake dispersed deionized water (DW) hybrid nanofluid system were developed first time to evaluate conductivity (TC) enhancements along with analysis TC behavior implementing modified effective medium theories (EMTs). A solvo-thermal two-step method was used develop MH nanoparticle exfoliated Gr nanofluids different compositions. Stability as-prepared monitored using Ultraviolet-Visible (UV-Vis) spectroscopy. The maximum sedimentation rate observed ~ 8.4 % after 600 hours. results showed an overall enhancement 43 at 25 °C. EMTs consideration flat geometry flake. It is found that, crumpled factor (due non-flatness or crumple flake) 0.205 predicted agreed experimental TC’s Gr-NMP/MH-DW samples. estimated value flakes images also nearly similar (~ 0.232). This agreement exposed flake’s negligible thickness compared its extremely wide basal plane dimensions in have leading impacts on properties model opens new doors analyse insight thermophysical various types by introducing potential other parameters.