Thermal Conductivity Enhancement of Atomic Layer Deposition Surface-Modified Carbon Nanosphere and Carbon Nanopowder Nanofluids

Abstract

In this paper, we present a study on thermal conductivity and viscosity of nanofluids containing novel atomic layer deposition surface-modified carbon nanosphere (ALD-CNS) and carbon nanopowder (ALD-CNP) core-shell nanocomposites. The nanocomposites were produced by atomic layer deposition of amorphous TiO2. The nanostructures were characterised by scanning (SEM) and transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetry/differential thermal analysis (TG/DTA) and X-ray powder diffraction (XRD). High-concentration, stable nanofluids were prepared with 1.5, 1.0 and 0.5 vol% nanoparticle content. The thermal conductivity and viscosity of the nanofluids were measured, and their stability was evaluated with Zeta potential measurements. The ALD-CNS enhanced the thermal conductivity of the 1:5 ethanol:water mixture by 4.6% with a 1.5 vol% concentration, and the viscosity increased by 37.5%. The ALD-CNS increased the thermal conductivity of ethylene–glycol by 10.8, whereas the viscosity increased by 15.9%. The use of a surfactant was unnecessary due to the ALD-deposited TiO2 layer.

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

“…Shang et al made Ag-Al 2 O 3 core–shell particles by atomic layer deposition to increase the optical absorption property of the Therminol66 base fluid [ 16 ]. Previously, there were only a few articles about the effect of ALD-modified nanoparticles on the heat transfer properties of a colloid system [ 21 ], and the feature of our composite nanofluids has never been investigated.…”

Thermophysical Properties of Nanocolloids and Their Potential Applications

“…Several articles were received, and with the help of our experienced reviewers, 10 papers were selected for publication [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. From a statistical data perspective, the reader should note that the articles had already received 29 citations and 9243 visualizations at the time of the writing of this Editorial.…”