Volumetric Properties and Surface Tension of Few-Layer Graphene Nanofluids Based on a Commercial Heat Transfer Fluid

Samah Hamze,David Cabaleiro,Patrice Estellé,Luis Lugo,Thierry Maré,Dominique Bégin,Alexandre Desforges,Brigitte Vigolo

doi:10.3390/en13133462

Abstract

Volumetric properties such as density and isobaric thermal expansivity, and surface tension are of paramount importance for nanofluids to evaluate their ability to be used as efficient heat transfer fluids. In this work, the nanofluids are prepared by dispersing few-layer graphene in a commercial heat transfer fluid Tyfocor® LS (40:60 wt.% propylene-glycol/water) with the aid of three different nonionic surfactants: Triton X-100, Pluronic® P-123 and Gum Arabic. The density, isobaric thermal expansivity and surface tension of each of the base fluids and nanofluids are evaluated between 283.15 and 323.15 K. The influence of the mass content in few-layer graphene from 0.05 to 0.5% on these nanofluid properties was studied. The density behavior of the different proposed nanofluids is slightly affected by the presence of graphene, and its evolution is well predicted by the weight-average equation depending on the density of each component of the nanofluids. For all the analyzed samples, the isobaric thermal expansivity increases with temperature which can be explained by a weaker degree of cohesion within the fluids. The surface tension evolution of the graphene-based nanofluids is found to be sensitive to the used surfactant, its content and the few-layer graphene concentration.

Highlights

Nanofluids are suspensions of nanoparticles (1–100 nm in size) dispersed in base fluids commonly used in heat transfer processes [1]
Few-layer graphene (FLG) produced following a mechanical exfoliation method was used to develop nanofluids considering a commercial heat transfer fluid based on a mixture of water and propylene glycol and different nonionic surfactants
These nanofluids were experimentally characterized in terms of density and surface tension in a wide temperature range varying the mass content in few-layer graphene (FLG) from 0.05 to 0.5%

Summary

Introduction

Nanofluids are suspensions of nanoparticles (1–100 nm in size) dispersed in base fluids commonly used in heat transfer processes [1]. These engineering materials are potentially attractive for many applications in the energy field including cooling engines and electronic circuits or increasing and recovering solar thermal energy [2]. The enhancement of thermal performance has become a key issue in the energy field considering the rapid growth in energy consumption worldwide [3,4,5]. Many studies have reported enhancement of thermal conductivity and heat transfer performance of nanofluids. Carbon nanomaterials are of major interest in this field due to their excellent intrinsic thermal properties, which are superior to Energies 2020, 13, 3462; doi:10.3390/en13133462 www.mdpi.com/journal/energies

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