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Preparation and rheological behavior of ethylene glycol-based TiO 2 nanofluids

2016; Elsevier BV; Volume: 509; Linguagem: Inglês

10.1016/j.colsurfa.2016.08.091

1873-4359

Ruiwen Shu, Ying Gan, Haoyuan Lv, Dexin Tan,

Enhanced Oil Recovery Techniques

In this work, the ethylene glycol-based TiO2 (EG/TiO2) nanofluids were prepared by dispersing TiO2 nanoparticles into the base fluid of EG via ultrasonication. The rheological behavior of EG/TiO2 nanofluids over 25–45 °C and particle weight concentration of 0–35 wt% were investigated. It was found that the steady state shear viscosity of the nanofluids was remarkably enhanced compared with the base fluid of EG. Moreover, the nanofluids showed a characteristic shear thinning behavior particularly at particle concentrations in excess of ∼5 wt%. Significantly, a Newtonian-pseudoplastic transition with a critical exponent of 3.2 was firstly observed as particle concentration increased, suggesting that the nanofluids had entered into the semi-diluted regime and some TiO2 nanoparticles were assembled into agglomerations. In addition, the results of shear viscosity curves and thixotropic loops at different temperature demonstrated that temperature had a remarkable influence on the nonlinear rheological behavior of the concentrated nanofluids. Therefore, the present study could shed light on the processing and application of TiO2-related nanofluids and nanocomposites.