Document type
Conference papers
Document subtype
Abstract
Title
Thermal Conductivity of Ionic Liquids and IoNanofluids. What is the situation?
Participants in the publication
Xavier Paredes (Author)
Dep. Química e Bioquímica
Maria José V. Lourenço (Author)
Dep. Química e Bioquímica
CQE
Carlos A. Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE
W. A. Wakeham (Author)
University of Southampton
Summary
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. Apart from the difficulties in measuring accurately the thermal conductivity of ionic melts and nanofluids [1] let many academia and industry to use software packages to estimate this property. \n\nIt is the purpose of this contribution 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 [2,3] and estimation methods previously developed for the base fluid [4]. In addition, we consider for IoNanofluids methods that emphasize the importance of the interfacial area IL-NM in modelling the thermal conductivity enhancement [5]. \n\nResults 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 [6] and Hamilton and Crosser [7] are not capable of estimating the thermal conductivity enhancement of IoNanofluids, and it is clear that the Murshed, Leong and Yang [8] model is not practical, if no additional information, either using imaging techniques at nanoscale or molecular dynamics simulations, is available.\n[1] - C.A. Nieto de Castro, M.J.V. Lourenço. Towards the Correct Measurement of Thermal Conductivity of Ionic Melts and Nanofluids. Energies 2020, 13, 99. DOI: https://doi.org/10.3390/en13010099 \n[2] ¬- Bridgman, P.W. The Thermal Conductivity of Liquids. Proc. Natl. Acad. Sci. USA 1923, 9, 341–345. DOI: https://doi.org/10.1073/pnas.9.10.341\n[3] - Biddle, J.W.; Holten, V.; Sengers, J.V.; Anisimov, M.A. Thermal conductivity of supercooled water. Phys. Rev. E, 2013, 87, 042302. DOI: https://doi.org/10.1103/PhysRevE.87.042302 \n[4] - Koller, T.M.; Schmid, S.R.; Sachnov, S.J.; Rausch, M.H.; Wasserscheid, P.; Fröba, A.P. Measurement and Prediction of the Thermal Conductivity of Tricyanomethanide- and Tetracyanoborate-Based Imidazolium Ionic Liquids. Int. J. Thermophys., 2014, 35, 195–217. DOI: https://doi.org/10.1007/s10765-014-1617-1 \n[5] - Paredes, X.; Lourenço, M.J.V.; Nieto de Castro, C.A.; Wakeham, W.A. Thermal Conductivity of Ionic Liquids and IoNanofluids. Can Molecular Theory Help? Fluids 2021, 6, 116. DOI: \nhttps://doi.org/10.3390/fluids6030116 \n[6] - Maxwell, J. C. A Treatise on Electricity and Magnetism, 3rd ed., 1891, Clarendon Press, Oxford, UK. \n[7] - R.L. Hamilton, O.K. Crosser. Thermal Conductivity of Heterogeneous Two-Component Systems. Ind. Eng. Chem. Fundament., 1962, 1, 187-191. DOI: https://doi.org/10.1021/i160003a005\n[8] - Leong, K.; Yang, C.; Murshed, S. A model for the thermal conductivity of nanofluids - the effect of interfacial layer. J. Nanopart. Res., 2006, 8(2), 245–254. DOI: https://doi.org/10.1007/s11051-005-9018-9
Date of Publication
2021-05-24
Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Event
6th Iberian Meeting on Ionic Liquids
Publication Identifiers
Address
online (COVID19)
Organizers
Universidad de Santiago de Chile