skip to main content

SciTech ConnectSciTech Connect

Title: Strong enhancement in thermal conductivity of ethylene glycol-based nanofluids by amorphous and crystalline Al{sub 2}O{sub 3} nanoparticles

In the present work, the temperature and concentration dependence of thermal conductivity (TC) enhancement in ethylene glycol (EG)-based amorphous and crystalline Al{sub 2}O{sub 3} nanofluids have been investigated at temperatures ranging from 0 to 100 °C. In our prior study, nanometer-sized particles of amorphous-, γ-, and α-Al{sub 2}O{sub 3} were prepared via a simple sol-gel process with annealing at different temperatures and characterized by various techniques. Building upon the earlier study, we probe here the crystallinity, microstructure, and morphology of the obtained α-Al{sub 2}O{sub 3} nanoparticles (NPs) by using X-ray powder diffraction with Rietveld full-profile refinement, scanning electron microscopy, and high-resolution transmission electron microscopy, respectively. In this study, we achieved a 74% enhancement in TC at higher temperature (100 °C) of base fluid EG by incorporating 1.0 vol. % of amorphous-Al{sub 2}O{sub 3}, whereas 52% and 37% enhancement is accomplished by adding γ- and α-Al{sub 2}O{sub 3} NPs, respectively. The amorphous phase of NPs appears to have good TC enhancement in nanofluids as compared to crystalline Al{sub 2}O{sub 3}. In a nutshell, these results are demonstrating the potential consequences of Al{sub 2}O{sub 3} NPs for applications of next-generation efficient energy transfer in nanofluids.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ; ;  [4]
  1. CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India)
  2. (India)
  3. Department of Physics, Panjab University, Chandigarh 160014 (India)
  4. Department of Physics, University of Allahabad, Allahabad 211002 (India)
Publication Date:
OSTI Identifier:
22318012
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; AMORPHOUS STATE; ENERGY TRANSFER; GLYCOLS; MICROSTRUCTURE; NANOPARTICLES; SCANNING ELECTRON MICROSCOPY; THERMAL CONDUCTIVITY; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION