Rheological characterization of polyethylene glycol based TiO2 nanofluids

Date

2014-11-01

Author

YAPICI, KERİM
KEKLİKCİOĞLU ÇAKMAK, NEŞE
Ilhan, Naciye
Uludağ, Yusuf

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

247
views

0
downloads

Rheological characterization of TiO2 nanoparticle dispersions in polyethylene glycol (PEG 200) is presented over 1-10 wt% particle mass fraction range in terms of shear viscosity, thixotropy and linear viscoelasticity. A stress controlled rheometer fitted by a cone-and-plate system was employed for the rheological measurements between -10 degrees C and 40 degrees C. The non-linear viscoelastic experiments revealed that TiO2-PEG 200 nanofluid exhibits a shear thinning behavior when particle mass fraction exceeds 1%. No appreciable change in the shear viscosity versus shear rate behavior was detected over the course of four days of dispersion storage. At high particle concentrations the dispersions had a yield stress that was determined by fitting the results through Herschel-Bukley model. Within the studied range of particle concentration, no evidence of thixotropic behavior was observed. In addition, relative viscosity measured at high shear region was found to be independent of the temperature. On the other hand, strong temperature dependency was observed at low shear region particularly at high temperatures. Storage and loss moduli of the TiO2-PEG 200 nanofluid were determined by frequency sweep measurements with applied stresses in the linear viscoelastic region. It was found that when the applied stress is lower than the corresponding yield stress TiO2-PEG 200 nanofluid showed a gel structure especially at high particle mass concentration.

Subject Keywords

TiO2 nanoparticles, Nanofluids, Non-Newtonian fluid, Rheology

URI

https://hdl.handle.net/11511/47611

Journal

KOREA-AUSTRALIA RHEOLOGY JOURNAL

DOI

https://doi.org/10.1007/s13367-014-0041-1

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

Interference studies in slotted silica tube trap technique Korkmaz, D; Mahmut, M; Helles, R; Ertas, N; Ataman, Osman Yavuz (2003-01-01) Interference effects of KCl, NH4H2PO4, (NH4)(2)CO3, MgCl2, NH4NO3, NaNO3, (NH4)(2)SO4, MgSO4.7H(2)O, CaCl2, Ca(NO3)(2) and NaCl on Bi, Cd, In, Pb and Sb were investigated using the atom trapping technique with a double slotted silica tube. Analyte solutions at concentration levels of 60, 6, 300, 75, 100 ng mL(-1) for Bi, Cd, In, Pb and Sb, respectively, were aspirated into an air-acetylene flame and analyte species were collected on the silica surface. Revolatilization was effected by aspirating IBMK at the...
Surface energy and excess charge in (1x2)-reconstructed rutile TiO2(110) from DFT plus U calculations Unal, Hatice; METE, ERSEN; Ellialtıoğlu, Süleyman Şinasi (2011-09-09) Physically reasonable electronic structures of reconstructed rutile TiO2(110)-(1x2) surfaces were studied using density functional theory (DFT) supplemented with Hubbard U on-site Coulomb repulsion acting on the d electrons, the so called DFT + U approach. Two leading reconstruction models proposed by Onishi and Iwasawa [Surf. Sci. Lett. 313, 783 (1994)] and Park and coworkers [Phys. Rev. B 75, 245415 (2007)] were compared in terms of their thermodynamic stabilities.
Thermal decomposition of polystyrene-b-poly(2-vinylpyridine) coordinated to co nanoparticles Elmaci, Ayşegül; Hacaloğlu, Jale; Kayran, Ceyhan; Sakellariou, Georgios; Hadjichristidis, Nikos (2009-11-01) Direct pyrolysis mass spectrometry analyses of polystyrene-block-poly(2-vinylpyridne), PS-b-P2VP, indicated that the thermal degradation of each component occurred independently through the decomposition pathways proposed for the corresponding homopolymers; depolymerization for PS and depolymerization and loss of protonated oligomers for P2VP by a more complex degradation mechanism. On the other hand, upon coordination to cobalt nanoparticles, thermal decomposition of the P2VP blocks was initiated by loss o...
Experimental investigation of drag reduction effects of polymer additives on turbulent pipe flow using ultrasound Doppler velocimetry Zeybek Vural, Serife; Bayram, Göknur; Uludağ, Yusuf (The Scientific and Technological Research Council of Turkey, 2014-01-01) Drag reduction in fully developed turbulent pipe flow with 4 concentrations (200 to 500 wppm or mg/kg) of low molecular weight sodium carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. Maximum drag reduction achieved was 22% using 500 wppm CMC solution. To observe the impact of the presence of CMC on the flow, ultrasound Doppler velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. Expe...
Controlled release of vancomycin from biodegradable microcapsules Ozalp, Y; Ozdemir, N; Kocagoz, S; Hasırcı, Vasıf Nejat (2001-01-01) Poly D,L-lactic acid (PLA) and its copolymers with glycolide PLGA 90:10 and 70:30 were polymerized under various conditions to yield polymers in the molecular weight range 12 000-40 000 daltons, as determined by gel permeation chromatography. Vancomycin hydrochloride was the hydrophilic drug of choice for the treatment of methicillin resistant Staphyloccoccal infections. It was microencapsulated in the synthesized polymers using water-oil-water (w/o/w) double emulsion and solvent evaporation. The influence ...

Citation Formats

K. YAPICI, N. KEKLİKCİOĞLU ÇAKMAK, N. Ilhan, and Y. Uludağ, “Rheological characterization of polyethylene glycol based TiO2 nanofluids,” KOREA-AUSTRALIA RHEOLOGY JOURNAL, pp. 355–363, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47611.