Special Issue "Thermophysical Properties of Nanofluids - From Measurement to Interpretation"

A special issue of Fluids (ISSN 2311-5521).

Deadline for manuscript submissions: closed (31 December 2020).

Special Issue Editors

Prof. Dr. Carlos A. Nieto De Castro
E-Mail Website
Guest Editor
Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
Interests: molecular chemistry; applied thermodynamics; thermophysical properties; ionic liquids; nanofluids; molten salts
Dr. Luis Lugo
E-Mail Website
Guest Editor
Department of Applied Physics, University of Vigo, 36310 Vigo, Spain
Interests: nanofluids; heat transfer fluids; lubricants; thermophysical properties; rheology
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Thermophysics is the science and technology of some of the most important properties of materials. Thermophysical properties are all material properties affecting the transfer and storage of heat, that vary with the composition and state variables such as temperature and pressure without altering the material’s chemical identity. Thermophysical properties play an important role in several processes in the chemical, extraction and manufacturing industries, especially in those involving simultaneous heat and mass transfer. Most of the problems that affect our society need values of these properties to design control and characterize new products and processes, to replace unacceptable processes and compounds and to optimize energy balances and efficiency.

Nanofluids appeared in the last decades as one of the hottest research fields, as it can been shown from the exponential growth of research publications. However, the progress measuring thermophysical properties and understanding of the structure of complex bi- or multiphasic systems or the mechanisms responsible for the anomalous thermal properties and heat transfer behavior, have/present large gaps and has been slower than desirable. This situation limits the sustainability of industrial/medical applications of nanofluids, as alternative engineering fluids.

It is the purpose of this special issue to contribute to an update of the different topics, either reviews, full papers or short contributions. It will constitute by several invited papers, and then, by open contributions. All the papers will follow the normal reviewing system of Fluids Journal.

As in topics of the different thermophysical properties conferences, papers on thermal conductivity, thermal diffusivity, viscosity and non-Newtonian properties, mass-diffusion, optical and radiative properties including emissivity, reflectivity and absorptivity, solubility, phase equilibrium including liquid-solid, calorimetric and volumetric properties, speed of sound, interfacial properties including solid-solid and wettability, as well as their importance in the chemical, extraction and manufacturing industries, in energy and environmental applications, will be accepted. Papers are welcomed on current research trends like:

1) Nanofluids for nuclear engineering

2) Nanofluids for thermal storage

3) Molten salts for solar applications

4) Soft materials (textiles, food products, body fluids)

5) Nanofluids and IoNanofluids (nonaqueous and high temperature)

6) New lubricants.

Prof. Carlos A. Nieto De Castro
Dr. Luis Lugo
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fluids is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • thermophysical properties
  • nanofluid
  • experimental methods
  • theory
  • molecular simulation
  • technological importance
  • environment
  • heat transfer
  • rheology
  • energy
  • nanosystems

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
Thermal Conductivity of Ionic Liquids and IoNanofluids. Can Molecular Theory Help?
Fluids 2021, 6(3), 116; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids6030116 - 12 Mar 2021
Viewed by 558
Abstract
Ionic liquids have been suggested as new engineering fluids, specifically in the area of heat transfer, and as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C, posing some environmental problems. Addition of nanoparticles [...] Read more.
Ionic liquids have been suggested as new engineering fluids, specifically in the area of heat transfer, and as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C, posing some environmental problems. Addition of nanoparticles to produce stable dispersions/gels of ionic liquids has proved to increase the thermal conductivity of the base ionic liquid, potentially contributing to better efficiency of heat transfer fluids. It is the purpose of this paper to analyze the prediction and estimation of the thermal conductivity of ionic liquids and IoNanofluids as a function of temperature, using the molecular theory of Bridgman and estimation methods previously developed for the base fluid. In addition, we consider methods that emphasize the importance of the interfacial area IL-NM in modelling the thermal conductivity enhancement. Results obtained show that it is not currently possible to predict or estimate the thermal conductivity of ionic liquids with an uncertainty commensurate with the best experimental values. The models of Maxwell and Hamilton are not capable of estimating the thermal conductivity enhancement of IoNanofluids, and it is clear that the Murshed, Leong and Yang model is not practical, if no additional information, either using imaging techniques at nanoscale or molecular dynamics simulations, is available. Full article
Show Figures

Figure 1

Article
Thermophysical Properties of Nanofluids Composed of Ethylene Glycol and Long Multi-Walled Carbon Nanotubes
Fluids 2020, 5(4), 241; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids5040241 - 12 Dec 2020
Cited by 3 | Viewed by 757
Abstract
In this work, thermal conductivity, viscosity, isobaric heat capacity, and density of stable carbon-based nanofluids are presented. The nanofluids under study are composed of 1,2-ethanediol (ethylene glycol, EG) and long multi-walled carbon nanotubes (MWCNTs), so-called ‘in-house 16h’ (synthesized in our laboratory via catalytic [...] Read more.
In this work, thermal conductivity, viscosity, isobaric heat capacity, and density of stable carbon-based nanofluids are presented. The nanofluids under study are composed of 1,2-ethanediol (ethylene glycol, EG) and long multi-walled carbon nanotubes (MWCNTs), so-called ‘in-house 16h’ (synthesized in our laboratory via catalytic chemical vapor deposition during 16 h with a diameter of 60–80 nm and length of 770 μm). Poly(N-vinylpyrrolidone) (PVP) was used to increase the stability of nanofluids. The nanofluids were prepared via an ultrasonication-assisted, three-step method while their key thermophysical characteristics were obtained using the hot-wire technique and rotary viscometer. As a result, the addition of MWCNTs significantly improved the thermal conductivity of nanofluids by 31.5% for the highest 1.0 wt% (0.498 vol%) long MWCNT content, leaving the Newtonian character of the nanofluids practically intact. Full article
Show Figures

Figure 1

Article
Thermophysical Properties of IoNanofluids Composed of 1-ethyl-3-methylimidazolium Thiocyanate and Carboxyl-functionalized Long Multi-walled Carbon Nanotubes
Fluids 2020, 5(4), 214; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids5040214 - 20 Nov 2020
Cited by 3 | Viewed by 750
Abstract
The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies [...] Read more.
The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies on the morphology and physicochemistry of carbon-based nanomaterials affecting thermal conductivity, viscosity, and density of INFs. We focus on the characterization of dispersions composed of long carboxylic group-functionalized multi-walled carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate. The thermal conductivity of INFs was measured using KD2 Pro Thermal Properties Analyzer (Decagon Devices Inc., Pullman, WA, USA). The viscosity was investigated using rotary viscometer LV DV-II+Pro (Brookfield Engineering, Middleboro, MA, USA). The density of INFs was measured using a vibrating tube densimeter Anton Paar DMA 5000 (Graz, Austria). The maximum thermal conductivity enhancement of 22% was observed for INF composed of 1 wt% long carboxylic group-functionalized multi-walled carbon nanotubes. Full article
Show Figures

Graphical abstract

Article
Heat-Dissipation Performance of Nanocomposite Phase-Change Materials in a Twin-Heat-Source System
Fluids 2020, 5(4), 174; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids5040174 - 07 Oct 2020
Cited by 1 | Viewed by 443
Abstract
In this paper, pure paraffin was mixed with CuO (high thermal conductivity) and Span-80 (as a dispersant). The CuO/paraffin nanocomposite phase-change materials (PCMs) were synthesized with mass fractions of 0.3%, 0.6%, and 1.2%, by a two-step method. Heat-transfer characteristics of the heat-pipe–PCMs module [...] Read more.
In this paper, pure paraffin was mixed with CuO (high thermal conductivity) and Span-80 (as a dispersant). The CuO/paraffin nanocomposite phase-change materials (PCMs) were synthesized with mass fractions of 0.3%, 0.6%, and 1.2%, by a two-step method. Heat-transfer characteristics of the heat-pipe–PCMs module and effects of fan power and heating power on the performance of the cooling module in a twin-heat-source system were studied. For two heat sources under 10 W–10 W (heat source 1 with a power of 10 W and heat source 2 with a power of 10 W), the paraffin wax decreases the evaporator temperature by 14.4%, compared with cases without PCMs. Full article
Show Figures

Figure 1

Article
Experimental Studies on Thermophysical and Electrical Properties of Graphene–Transformer Oil Nanofluid
Fluids 2020, 5(4), 172; https://doi.org/10.3390/fluids5040172 - 03 Oct 2020
Cited by 2 | Viewed by 740
Abstract
The thermophysical and electrical properties of graphene–transformer oil nanofluid at three weight percentage concentrations (0.01%, 0.03%, and 0.05%) were experimentally studied. Experiments conducted to find viscosity, surface tension, density, specific resistance, electrical conductivity, and dielectric dissipation at various temperatures ranging from 20 °C [...] Read more.
The thermophysical and electrical properties of graphene–transformer oil nanofluid at three weight percentage concentrations (0.01%, 0.03%, and 0.05%) were experimentally studied. Experiments conducted to find viscosity, surface tension, density, specific resistance, electrical conductivity, and dielectric dissipation at various temperatures ranging from 20 °C to 90 °C. It was noted that the nanofluid with 0.05% concentration showed an enhancement of 2.5% and 16.6% for density and viscosity, respectively, when compared to transformer oil. In addition, an average reduction in surface tension is noted to be 10.1% for the maximum concentration of nanofluid. Increase in heat load and concentration improves Brownian motion and decreases the cohesive force between these particles, which results in a reduction in surface tension and increases the heat-transfer rate compared to transformer oil. In addition, for the maximum concentration of nanoparticles, the electrical conductivity of nanofluid was observed to be 3.76 times higher than that of the transformer oil at 90 °C. The addition of nanoparticles in the transformer oil decreases the specific resistance and improves the electrical conductivity thereby enhancing the breakdown voltage. Moreover, the thermophysics responsible for the improvement in thermophysical and electrical properties are discussed clearly, which will be highly useful for the design of power transmission/distribution systems. Full article
Show Figures

Figure 1

Review

Jump to: Research

Review
Analysis of the Parameters Required to Properly Define Nanofluids for Heat Transfer Applications
Fluids 2021, 6(2), 65; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids6020065 - 02 Feb 2021
Cited by 2 | Viewed by 671
Abstract
Nanofluids are obtained by dispersing nanoparticles and dispersant, when present, in a base fluid. Their properties, in particular their stability, however, are strictly related to several other parameters, knowledge of which is important to reproduce the nanofluids and correctly interpret their behavior. Due [...] Read more.
Nanofluids are obtained by dispersing nanoparticles and dispersant, when present, in a base fluid. Their properties, in particular their stability, however, are strictly related to several other parameters, knowledge of which is important to reproduce the nanofluids and correctly interpret their behavior. Due to this complexity, the results appear to be frequently unreliable, contradictory, not comparable and/or not repeatable, in particular for the scarcity of information on their preparation. Thus, it is essential to define what is the minimum amount of information necessary to fully describe the nanofluid, so as to ensure the possibility of reproduction of both their formulation and the measurements of their properties. In this paper, a literature analysis is performed to highlight what are the most important parameters necessary to describe the configuration of each nanofluid and their influence on the nanofluid’s properties. A case study is discussed, analyzing the information reported and the results obtained for the thermophysical properties of nanofluids formed by water and TiO2 nanoparticles. The aim is to highlight the differences in the amount of information given by the different authors and exemplify how results can be contradictory. A final discussion gives some suggestions on the minimum amount of information that should be given on a nanofluid to have the possibility to compare results obtained for similar nanofluids and to reproduce the same nanofluid in other laboratories. Full article
Show Figures

Graphical abstract

Back to TopTop