Sadri, Rad and Hosseini, Maryam and Kazi, Salim Newaz and Bagheri, Samira and Abdelrazek, Ali H. and Ahmadi, Goodarz and Zubir, Mohd Nashrul Mohd and Ahmad, Roslina and Abidin, Nor Ishida Zainal (2018) A facile, bio-based, novel approach for synthesis of covalently functionalized graphene nanoplatelet nano-coolants toward improved thermo-physical and heat transfer properties. Journal of Colloid and Interface Science, 509. pp. 140-152. ISSN 0021-9797, DOI https://doi.org/10.1016/j.jcis.2017.07.052.
Full text not available from this repository.Abstract
In this study, we synthesized covalently functionalized graphene nanoplatelet (GNP) aqueous suspensions that are highly stable and environmentally friendly for use as coolants in heat transfer systems. We evaluated the heat transfer and hydrodynamic properties of these nano-coolants flowing through a horizontal stainless steel tube subjected to a uniform heat flux at its outer surface. The GNPs functionalized with clove buds using the one-pot technique. We characterized the clove-treated GNPs (CGNPs) using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). We then dispersed the CGNPs in distilled water at three particle concentrations (0.025, 0.075 and 0.1 wt%) in order to prepare the CGNP-water nanofluids (nano-coolants). We used ultraviolet–visible (UV–vis) spectroscopy to examine the stability and solubility of the CGNPs in the distilled water. There is significant enhancement in thermo-physical properties of CGNPs nanofluids relative those for distilled water. We validated our experimental set-up by comparing the friction factor and Nusselt number for distilled water obtained from experiments with those determined from empirical correlations, indeed, our experimental set-up is reliable and produces results with reasonable accuracy. We conducted heat transfer experiments for the CGNP-water nano-coolants flowing through the horizontal heated tube in fully developed turbulent condition. Our results are indeed promising since there is a significant enhancement in the Nusselt number and convective heat transfer coefficient for the CGNP-water nanofluids, with only a negligible increase in the friction factor and pumping power. More importantly, we found that there is a significant increase in the performance index, which is a positive indicator that our nanofluids have potential to substitute conventional coolants in heat transfer systems because of their overall thermal performance and energy savings benefits.
| Item Type: | Article |
|---|---|
| Funders: | University of Malaya , Malaysia under the University of Malaya Research Grant Scheme (Project no.: GC001D-14AET), RP012C-13AET and Fundamental Research Grant Scheme (Project no.: FRGS-FP056-2016) |
| Uncontrolled Keywords: | Eco-friendly synthesis; Functionalization; Nanofluids; Thermo-physical properties; Carbon nanoparticles; Graphene nanoplatelets (GNPs); Convective heat transfer |
| Subjects: | T Technology > TJ Mechanical engineering and machinery |
| Divisions: | Faculty of Engineering Deputy Vice Chancellor (Research & Innovation) Office > Nanotechnology & Catalysis Research Centre |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 08 Apr 2019 07:30 |
| Last Modified: | 08 Apr 2019 07:30 |
| URI: | http://eprints.um.edu.my/id/eprint/20835 |
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