Few-Layer Graphene-Based Nanofluids with Enhanced Thermal Conductivity.

Samah Hamze,David Cabaleiro,Thierry Maré,Patrice Estellé,Brigitte Vigolo,Nawal Berrada,Jérôme Gleize,Jaafar Ghanbaja,Dominique Bégin,Florentin Michaux,Alexandre Desforges

doi:10.3390/nano10071258

Abstract

High-quality graphene is an especially promising carbon nanomaterial for developing nanofluids for enhancing heat transfer in fluid circulation systems. We report a complete study on few layer graphene (FLG) based nanofluids, including FLG synthesis, FLG-based nanofluid preparation, and their thermal conductivity. The FLG sample is synthesized by an original mechanical exfoliation method. The morphological and structural characterization are investigated by both scanning and transmission electron microscopy and Raman spectroscopy. The chosen two-step method involves the use of thee nonionic surfactants (Triton X-100, Pluronic® P123, and Gum Arabic), a commercial mixture of water and propylene glycol and a mass content in FLG from 0.05 to 0.5%. The thermal conductivity measurements of the three FLG-based nanofluid series are carried out in the temperature range 283.15–323.15 K by the transient hot-wire method. From a modeling analysis of the nanofluid thermal conductivity behavior, it is finally shown that synergetic effects of FLG nanosheet size and thermal resistance at the FLG interface both have significant impact on the evidenced thermal conductivity enhancement.

Highlights

The growth in energy consumption pushes us to make an energy transition to low carbon generation and design more efficient utilization approaches, which requires a research effort focused on the development of innovative, intelligent, durable, and effective solutions [1]
The results showed an enhancement in the thermal conductivity of nanofluids by more than 25% for different temperatures and weight fraction of 0.01%
The as-produced high-quality few layer graphene (FLG) is used for the production of graphene based-nanofluids prepared with a commercial heat transfer fluid, namely Tyfocor® LS, which is a mixture of propylene glycol:water (40:60) wt.% [52]

Summary

Introduction

The growth in energy consumption pushes us to make an energy transition to low carbon generation and design more efficient utilization approaches, which requires a research effort focused on the development of innovative, intelligent, durable, and effective solutions [1]. Bahaya et al [38] focused on the graphene nanosheets (diameter 5 μm and thickness 3 nm) dispersed in water with the addition of gelatin to prevent the sedimentation The authors prepared their nanofluids with nanoparticle concentrations up to 0.014% in volume. Amiri et al focused on mono-layer graphene nanoparticles dispersed in water with different weight contents between 0.005 and 0.01% [49] They found an increase in thermal conductivity values with increasing temperature from 283.15 to 323.15 K. The as-produced high-quality FLG is used for the production of graphene based-nanofluids prepared with a commercial heat transfer fluid, namely Tyfocor® LS, which is a mixture of propylene glycol:water (40:60) wt.% [52] These nanofluids were produced when considering Triton X-100, Pluronic® P-123, and Gum Arabic as surfactants. The thermal conductivity of the FLG-based nanofluids was analyzed with relevant models while taking the influence of several parameters, such as the average length, interfacial thermal resistance, thickness, or flatness ratio of FLG, into consideration in order to provide a further insight that could help to understand the reasons behind the thermal conductivity enhancements in such prepared graphene-based nanofluids

Materials

Findings

Characterization Techniques