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Viscosity affected by nanoparticle aggregation in Al2O3-water nanofluids

Fei Duan*, Dingtian Kwek and Alexandru Crivoi

Author affiliations

School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore

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Citation and License

Nanoscale Research Letters 2011, 6:248  doi:10.1186/1556-276X-6-248

Published: 22 March 2011

Abstract

An investigation on viscosity was conducted 2 weeks after the Al2O3-water nanofluids having dispersants were prepared at the volume concentration of 1-5%. The shear stress was observed with a non-Newtonian behavior. On further ultrasonic agitation treatment, the nanofluids resumed as a Newtonian fluids. The relative viscosity increases as the volume concentrations increases. At 5% volume concentration, an increment was about 60% in the re-ultrasonication nanofluids in comparison with the base fluid. The microstructure analysis indicates that a higher nanoparticle aggregation had been observed in the nanofluids before re-ultrasonication.