Carbon nanotube glycol nanofluids: Photo-thermal properties, thermal conductivities and rheological behavior--颗粒学报PARTICUOLOGY

Meng, Z., Wu, D., Wang, L., Zhu, H., & Li, Q. (2012). Carbon nanotube glycol nanofluids: Photo-thermal properties, thermal conductivities and rheological behavior. Particuology, 10(5), 614–618. https://doi.org/10.1016/j.partic.2012.04.001

Carbon nanotube glycol nanofluids: Photo-thermal properties, thermal conductivities and rheological behavior

Zhaoguo Meng ^{a b}, Daxiong Wu ^a, Liangang Wang ^a, Haitao Zhu^a *, Qingling Li ^b

a College of Materials Science & Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
b College of Electromechanical Engineering, Qingdao University of Science & Technology, Qingdao 266042, China

10.1016/j.partic.2012.04.001

Volume 10, Issue 5, October 2012, Pages 614-618

Received 30 December 2011, Revised 27 March 2012, Accepted 6 April 2012, Available online 4 June 2012.

E-mail: htzhu1970@163.com

Highlights

► CNTs glycol nanofluid, prepared by supersonic dispersing after oxidation treatment with HNO₃, had strong absorption for sunlight.

► Enhancement of photo-thermal conversion was 18% for 0.5 wt% nanofluid at 25 °C.

► Nanofluids with 4.0 wt% CNTs exhibited lower viscosity and 25.4% higher thermal conductivity at 55 °C compared to that of pure glycol at 25 °C.

Abstract

The efficiency and effectiveness of solar energy capture and storage are to a large extent functions of the heat transfer and storage capacity of the medium used. This paper investigates the potential of using carbon nanotube (CNT)-glycol nanosuspension as such a medium, prepared by freeze drying-ultrasonic dispersing after oxidation treatment with HNO₃. The influences of the mass fraction of CNTs glycol nanofluids and temperatures on photo-thermal properties, thermal conductivities and rheological behavior were investigated. The results show that CNTs with oxidation treatment exhibited good dispersing performance. Strong optical absorption of the CNTs glycol nanofluids was detected in the range of 200–2500 nm. At room temperature, 18% enhancement was found in the photo-thermal conversion efficiency of the 0.5% mass fraction CNTs glycol nanofluids in comparison to the basic fluids, without significant increase in viscosity. At 55 °C, CNTs glycol nanofluids with 4.0% mass fraction exhibited much lower viscosity and 25.4% higher thermal conductivity in comparison to that of pure glycol at room temperature.

Graphical abstract

Keywords

Nanofluids; CNTs; Photo-thermal conversion; Rheological behavior; Thermal conductivity

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