Qualitative investigations on the stability of Al₂O₃-SiO₂ hybrid water-based nanofluids

Abstract

Qualitative experiments were carried out to investigate the stability of Al2O3-SiO2 hybrid water-based nanofluids. The main nanoparticles used in this work were Al2O3 and SiO2 since these types of nanoparticles has been widely used and proposed in many applications and information on their hybrid dispersion stability characteristic are still elusive. The present work demonstrated the stability of Al2O3-SiO2 hybrid nanofluids using various preparation techniques and successively elucidating the optimum preparation method for hybrid nanofluid. The hybrid water-based nanofluid were prepared by dispersing a 50:50 ratio of Al2O3-SiO2 nanoparticles into distilled water to achieve total volume concentration of C=0.001, 0.01 and 0.1 vol%. Successively, the hybrid nanofluids were prepared using magnetic stirrer and ultrasonic bath. The samples are categorised into five preparation method which are: (i) 1 hour sonication, (ii) 1 hour magnetic stirrer, (iii) 0.25 hour magnetic stirrer and 1 hour sonication, and (iv) 0.5 hour magnetic stirrer and 1 hour sonication and (v) without magnetic stirring and sonication. The height of sedimentation and colloidal stability of each preparation methods were observed in the duration of 2 weeks. In the present work, it was observed that the dispersion stability of hybrid nanofluids prepared by applying magnetic stirrer for 15 minutes with prior to 1 hour of sonication had demonstrated the highest stability indicated by the lowest height of sedimentation and high colloidal stability.

Heat Transfer Characteristics of Metallic Body during Quenching in Saturated Nanofluids

“…The measured weight was then converted into the volume of the nanoparticles and then successively suspended in the designated volume of the base fluid to achieve a concentration of C= 0.001 vol%. Prior to the final dilution process, the suspension was then stirred for 15 minutes using a magnetic stirrer to achieve homogeneity and was then sonicated in an ultrasonic bath (Bransonic® CPXH Ultrasonic Bath) for 1 hour just before the experiments were conducted, based on our previous work [26]. During the preparation process, no dispersant or surfactant was added to avoid altering the fluid's chemical and thermo-physical properties.…”

Investigation into the Size Distribution of Al₂O₃- ZnO Nanoparticles Dispersed in DI Water and Following the Impact of CNTs on the Stability, Heat Transfer, and Electricity Transfer of Al₂O₃- ZnO-CNT Hybrid Nanofluid

“…Their measurements revealed that the values of zeta potential for all ratios were in the range of ±27 ~ +39.54 mV, which indicates a moderate upward stability. Also, Ismail et al [13] applied a variety of ultrasonic and stirrer times for dispersing Al2O3-SiO2 hybrid nanofluid. Then, for two weeks, they measured the stability of the Al2O3-SiO2 hybrid nanofluid using an observation method.…”

Instability of Hydromagnetic Hybrid Flow Fe2O3-Fe3O4 /H2O of Thermocapillary Layers of Shear-Thinning Nanofluids

“…From his studies it is concluded that tri-hybrid nanoparticles effectively prepared and attained stability. The qualitative studies on the stability of Al2O3-SiO2 based water hybrid nanofluid was carried out by H. Ismail [23]. The enhanced stability, optical properties and high solar heat transformation competency of SiC-MWCNTs hybrid nanofluids for DASC applications was studied by Xiaoke Li [24].…”