Abstract
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 language | English |
|---|---|
| Pages (from-to) | 4923-4929 |
| Number of pages | 7 |
| Journal | Journal of Nanoscience and Nanotechnology |
| Volume | 8 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2008 Oct |
Keywords
- 3ω Method
- Colloidal stability
- Effective thermal conductivity
- Nanofluid
ASJC Scopus subject areas
- Bioengineering
- Chemistry(all)
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics