Experimental analysis on stability, characterization, and physical properties of hybrid magnetic clove-functionalized graphene Nanoplatelets/Fe₃O₄ Nanofluids

The current work experimentally investigates the characteristics, stability, and physical properties of clove-functionalized graphene nanoplatelets (CGNP)/Fe₃O₄ – Water nanofluids, exploring the effects of nanoparticle concentration (0–0.1 wt%), hybrid ratio (25:75, 50:50, 75:25), and temperature (22 °C – 65 °C). The hybrid magnetic nanofluids were thoroughly characterized, where stability was assessed utilizing several qualitative and quantitative methods. Results indicated increased densities and viscosities with higher nanoparticle concentrations, attributed to combined microscale and macroscale influences. On a molecular scale, as nanoparticle concentration increases the formation of additional interfacial layers contributes to higher densities. Furthermore, increasing nanoparticles concentration intensifies Brownian motion, leading to increased intermolecular interactions and fluid friction, thereby raising dynamic viscosities. Favoured Fe₃O₄ nanoparticle ratios, consistently yielded higher densities and viscosities, owing to the larger nanoparticle sizes, higher intrinsic densities, agglomeration tendency of Fe₃O₄ nanoparticles, and relatively enhanced interfacial layers. At the highest nanoparticle concentration of 0.1 wt% and favoured Fe₃O₄ 25:75 ratio, the hybrid nanofluids exhibited maximum density and viscosity enhancement of 0.65 % and 21.4 % respectively. The hybrid nanoparticles also enabled significant reduction in contact angles, up to 30.87 %. Where, higher concentrations and Fe₃O₄ ratios amplified wettability due to interfacial adsorption, cohesive force weakening, and enhanced adhesion to the substrate.