title: Viscosity affected by nanoparticle aggregation in Al2O3-water nanofluids.
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.
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore. feiduan@ntu.edu.sg.
authors.forename: Fei
authors.initials: F
authors.lastname: Duan
authors.forename: Dingtian
authors.initials: D
authors.lastname: Kwek
authors.forename: Alexandru
authors.initials: A
authors.lastname: Crivoi