Experimental Investigation of Rheological Properties and Thermal Conductivity of SiO2-TiO2 Composite Nanofluids Prepared by Atomic Layer Deposition

Zalán István Várady; Thong Le Ba; Bence Parditka; Zoltán Erdélyi; Klara Hernadi; Gábor Karacs; Gyula Gróf; Imre Miklós Szilágyi

doi:10.3390/nano12173014

Experimental Investigation of Rheological Properties and Thermal Conductivity of SiO₂-TiO₂ Composite Nanofluids Prepared by Atomic Layer Deposition

Nanomaterials (Basel). 2022 Aug 31;12(17):3014. doi: 10.3390/nano12173014.

Authors

Zalán István Várady¹, Thong Le Ba¹, Bence Parditka², Zoltán Erdélyi², Klara Hernadi³, Gábor Karacs⁴, Gyula Gróf⁵, Imre Miklós Szilágyi¹

Affiliations

¹ Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Muegyetem rakpart 3, 1111 Budapest, Hungary.
² Department of Solid-State Physics, Faculty of Science and Technology, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary.
³ Institute of Physical Metallurgy, Metal Forming and Nanotechnology, University of Miskolc, 3515 Miskolc-Egyetemváros, Hungary.
⁴ ELKH-ME Materials Science Research Group, ELKH, University of Miskolc, 3515 Miskolc-Egyetemváros, Hungary.
⁵ Centre of Energy Research, Konkoly-Thege Miklós út 29-33, 1121 Budapest, Hungary.

Abstract

In the current research, surface-modified SiO₂ nanoparticles were used upon immersion in an applied base fluid (ethylene glycol:water = 1:1). The atomic layer deposition method (ALD) was introduced to obtain a thin layer of TiO₂ to cover the surface of SiO₂ particles. After the ALD modification, the TiO₂ content was monitored by energy dispersive X-ray spectroscopy (EDS). Transmission electron microscopy (TEM) and FT-IR spectroscopy were applied for the particle characterization. The nanofluids contained 0.5, 1.0, and 1.5 volume% solid particles and zeta potential measurements were examined in terms of colloid stability. A rotation viscosimeter and thermal conductivity analyzer were used to study the nanofluids' rheological properties and thermal conductivity. These two parameters were investigated in the temperature range of 20 °C and 60 °C. Based on the results, the thin TiO₂ coating significant impacted these parameters.

Keywords: ALD; SiO2; TiO2 layer; composite nanoparticles; nanofluid; thermal conductivity; viscosity.

Abstract

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