Effect of particles size and surface modification on thermal conductivity and viscosity of alumina nanofluids
2013 (English)Conference paper, Poster (Refereed)
Electronics industry growing faster and it demands ultrahigh performance cooling systems to manage the heat loses in terms of energy and money. Conventional cooling fluids are approaching to its limit due to the poor thermal transport performance and a new era for the heat transfer fluids had been initiated about two decades ago. When nanoparticles dispersed in conventional heat transfer fluid (like water, oil, glycols), the mixture is called as nanofluids. Alumina suspensions are well known class of nanofluids, which have been investigated in many recent studies to determine the non-classical behavior of the suspensions. The aim of this study is to investigate optimized particle size and suitable surface modification for the improved dispersion properties of nanofluids with enhanced thermal performance and low viscosity. We have utilized two different types of alumina crystal phases; one is Boehmite (γ-AlOOH) and clay type (α -Al2O3) and the nanofluids were prepare d by suspending different size of nanoparticles in water and water/ethylene glycol (EG) mixtures. Dynamic light scattering (DLS) was used to determine the agglomerate size and scanning electron microscope (SEM) used to study the particle size and morphology. Zeta potential was measured to determine the electrostatic stability for the dispersed nanoparticles. Thermal conductivity was estimated by using KD2 Pro setup and up to 10 % enhancement in TC was observed as compared to the base fluid. Viscosity was measured by capillary viscometer, which shows the significant effect from the addition of additives and surfactants. Possible mechanisms contributing in reducing the viscosity and increasing the thermal conductivity are described in details.
Place, publisher, year, edition, pages
Alumina, Nanofluids, Thermal conductivity, Viscosity
IdentifiersURN: urn:nbn:se:kth:diva-124189OAI: oai:DiVA.org:kth-124189DiVA: diva2:633624
European Materials Research Conference E-MRS; Strasbourg, France, May 27-31, 2013
QC 201406262013-06-272013-06-272014-06-26Bibliographically approved