Journal of Nanoparticle Research

, Volume 11, Issue 5, pp 1129–1136 | Cite as

The effect of particle size on the thermal conductivity of alumina nanofluids

  • Michael P. Beck
  • Yanhui Yuan
  • Pramod Warrier
  • Amyn S. Teja
Research Paper


We present new data for the thermal conductivity enhancement in seven nanofluids containing 8–282 nm diameter alumina nanoparticles in water or ethylene glycol. Our results show that the thermal conductivity enhancement in these nanofluids decreases as the particle size decreases below about 50 nm. This finding is consistent with a decrease in the thermal conductivity of alumina nanoparticles with decreasing particle size, which can be attributed to phonon scattering at the solid–liquid interface. The limiting value of the enhancement for nanofluids containing large particles is greater than that predicted by the Maxwell equation, but is predicted well by the volume fraction weighted geometric mean of the bulk thermal conductivities of the solid and liquid. This observation was used to develop a simple relationship for the thermal conductivity of alumina nanofluids in both water and ethylene glycol.


Nanofluids Thermal conductivity Transient hot wire method Phonon scattering Nanoparticles Colloids 



Exponent of Euler’s constant


Thermal conductivity (W m−1 K−1)


Heat dissipated per length of wire (W m−1)


Radius of wire (m)


Temperature of wire (K)


Time (s)

Greek symbols


Thermal diffusivity of liquid (m2 s−1)


Volume fraction


Thermal conductivity enhancement







  1. Beck MP, Sun TF, Teja AS (2007) The thermal conductivity of alumina nanoparticles dispersed in ethylene glycol. Fluid Phase Equilib 260:275–278. doi:10.1016/j.fluid.2007.07.034 CrossRefGoogle Scholar
  2. Bleazard JG, Teja AS (1995) Thermal-conductivity of electrically conducting liquids by the transient hot-wire method. J Chem Eng Data 40:732–737. doi:10.1021/je00020a003 CrossRefGoogle Scholar
  3. Cahill DG, Ford WK, Goodson KE et al (2003) Nanoscale thermal transport. J Appl Phys 93:793–818. doi:10.1063/1.1524305 CrossRefADSGoogle Scholar
  4. Choi SUS, Zhang ZG, Yu W et al (2001) Anomalous thermal conductivity enhancement in nanotube suspensions. Appl Phys Lett 79:2252–2254. doi:10.1063/1.1408272 CrossRefADSGoogle Scholar
  5. Eastman JA, Choi SUS, Li S et al (1997) Enhanced thermal conductivity through the development of nanofluids. Mater Res Soc Symp Proc 457:3–11Google Scholar
  6. Eastman JA, Choi SUS, Li S et al (2001) Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles. Appl Phys Lett 78:718–720. doi:10.1063/1.1341218 CrossRefADSGoogle Scholar
  7. Fang KC, Weng CI, Ju SP (2006) An investigation into the structural features and thermal conductivity of silicon nanoparticles using molecular dynamics simulations. Nanotechnology 17:3909–3914. doi:10.1088/0957-4484/17/15/049 CrossRefADSGoogle Scholar
  8. Ge ZB, Cahill DG, Braun PV (2006) Thermal conductance of hydrophilic and hydrophobic interfaces. Phys Rev Lett 96:186101. doi:10.1103/PhysRevLett.96.186101 PubMedCrossRefADSGoogle Scholar
  9. Jang SP, Choi SUS (2006) Cooling performance of a microchannel heat sink with nanofluids. Appl Therm Eng 26:2457–2463. doi:10.1016/j.applthermaleng.2006.02.036 CrossRefGoogle Scholar
  10. Kim SH, Choi SR, Kim D (2007) Thermal conductivity of metal-oxide nanofluids: particle size dependence and effect of laser irradiation. J Heat Transf-Trans ASME 129:298–307. doi:10.1115/1.2427071 CrossRefMathSciNetGoogle Scholar
  11. Lee S, Choi SUS, Li S et al (1999) Measuring thermal conductivity of fluids containing oxide nanoparticles. J Heat Transf-Trans ASME 121:280–289. doi:10.1115/1.2825978 CrossRefGoogle Scholar
  12. Li CH, Peterson GP (2007) The effect of particle size on the effective thermal conductivity of Al2O3-water nanofluids. J Appl Phys 101:044312. doi:10.1063/1.2436472 CrossRefADSGoogle Scholar
  13. Li DY, Wu YY, Kim P et al (2003) Thermal conductivity of individual silicon nanowires. Appl Phys Lett 83:2934–2936. doi:10.1063/1.1616981 CrossRefADSGoogle Scholar
  14. Liu W, Asheghi M (2004) Phonon-boundary scattering in ultrathin single-crystal silicon layers. Appl Phys Lett 84:3819–3821. doi:10.1063/1.1741039 CrossRefADSGoogle Scholar
  15. Maiga SE, Nguyen CT, Galanis N et al (2006) Heat transfer enhancement in turbulent tube flow using Al2O3 nanoparticle suspension. Int J Numer Methods H 16:275–292. doi:10.1108/09615530610649717 CrossRefGoogle Scholar
  16. Marsh KN (ed) (1987) Recommended reference materials for the realization of physicochemical properties. Blackwell Scientific Publications, BostonGoogle Scholar
  17. Maxwell JC (1892) A treatise on electricity and magnetism. Oxford University Press, LondonGoogle Scholar
  18. Meyer CA (ed) (1993) ASME steam tables: thermodynamic and transport properties of steam. American Society of Mechanical Engineers, New YorkGoogle Scholar
  19. Nan CW, Birringer R, Clarke DR et al (1997) Effective thermal conductivity of particulate composites with interfacial thermal resistance. J Appl Phys 81:6692–6699. doi:10.1063/1.365209 CrossRefADSGoogle Scholar
  20. Prasher R, Evans W, Meakin P (2006) Effect of aggregation on thermal conduction in colloidal nanofluids. Appl Phys Lett 89:143119. doi:10.1063/1.2360229 CrossRefADSGoogle Scholar
  21. Sun TF, Teja AS (2004a) Density, viscosity, and thermal conductivity of aqueous benzoic acid mixtures between 375 K and 465 K. J Chem Eng Data 49:1843–1846. doi:10.1021/je0497247 CrossRefGoogle Scholar
  22. Sun TF, Teja AS (2004b) Density, viscosity and thermal conductivity of aqueous solutions of propylene glycol, dipropylene glycol, and tripropylene glycol between 290 K and 460 K. J Chem Eng Data 49:1311–1317. doi:10.1021/je049960h CrossRefGoogle Scholar
  23. Turian RM, Sung DJ, Hsu FL (1991) Thermal conductivity of granular coals, coal-water mixtures and multi-solid/liquid suspensions. Fuel 70:1157–1172. doi:10.1016/0016-2361(91)90237-5 CrossRefGoogle Scholar
  24. Wang XW, Xu XF, Choi SUS (1999) Thermal conductivity of nanoparticle-fluid mixture. J Thermophys Heat Transf 13:474–480. doi:10.2514/2.6486 CrossRefGoogle Scholar
  25. Wen DS, Ding W (2006) Natural convective heat transfer of suspensions of titanium dioxide nanoparticles (Nanofluids). IEEE Trans NanoTechnol 5:220–227. doi:10.1109/TNANO.2006.874045 CrossRefADSGoogle Scholar
  26. Xie HQ, Wang JC, Xi TG et al (2002) Thermal conductivity enhancement of suspensions containing nanosized alumina particles. J Appl Phys 91:4568–4572. doi:10.1063/1.1454184 CrossRefADSGoogle Scholar
  27. Yu W, France DM, Choi SUS et al (2007) Review and assessment of nanofluid technology for transportation and other applications. Argonne National Laboratory, Argonne, ILGoogle Scholar
  28. Ziambaras E, Hyldgaard P (2006) Phonon Knudsen flow in nanostructured semiconductor systems. J Appl Phys 99:054303. doi:10.1063/1.2175474 CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Michael P. Beck
    • 1
  • Yanhui Yuan
    • 1
  • Pramod Warrier
    • 1
  • Amyn S. Teja
    • 1
  1. 1.School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaUSA

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