Transient thermal conductivity and colloidal stability measurements of nanofluids by using the 3ω method

Dong Wook Oh, Ohmyoung Kwon, Joon Sik Lee

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


Nanofluid is a mixture of nanoscale particles of metal, metal oxide or carbon nanotube and heat transfer fluids such as water and ethylene glycol. This work presents the application of the 3-omega (3ω) method for measuring the colloidal stability and the transient thermal conductivity of multi-wall carbon nanotube (MWCNT), Al 2O 3 and TiO 2 nanoparticles suspended in water or ethylene glycol. The microfabricated 3ω device is verified by comparing the measured thermal conductivities of pure fluids with the table values. After the validation, the transient thermal responses of the nanofluids are measured to evaluate the colloidal stability. All of Al 2O 3 nanofluid samples show a clear sign of sedimentation while the acid-treated MWCNT (tMWCNT) nanofluid and a couple of TiO 2 nanofluids with pH control or surfactant addition are found to have excellent colloidal stability. The thermal conductivities of tMWCNT nanofluids in the de-ionized water and ethylene glycol are measured, which are found to be in good agreement with previous data.

Original languageEnglish
Pages (from-to)4923-4929
Number of pages7
JournalJournal of Nanoscience and Nanotechnology
Issue number10
Publication statusPublished - 2008 Oct


  • 3ω Method
  • Colloidal stability
  • Effective thermal conductivity
  • Nanofluid

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics


Dive into the research topics of 'Transient thermal conductivity and colloidal stability measurements of nanofluids by using the 3ω method'. Together they form a unique fingerprint.

Cite this