Characterization of Al$_{12}$Mg$_{17}$ Nanofluid By Dynamic Light Scattering and Beam Displacement Methods

TL;DR

This study investigates the thermal conductivity, stability, and particle size of Al$_{12}$Mg$_{17}$ nanofluids using novel optical methods, revealing optimal preparation conditions and significant thermal enhancements for cooling applications.

Contribution

It introduces a novel beam displacement method for measuring nanofluid thermal conductivity and provides comprehensive analysis of stability and particle size distribution for Al$_{12}$Mg$_{17}$ nanofluids.

Findings

Thermal conductivity increased by up to 40% at 0.05 vol.% nanoparticle concentration.

Optimal surfactant ratio of CTAB to nanoparticles was 1:1 for stability.

Peak particle size was 154 nanometers after 2 hours of ultrasonication.

Abstract

The thermal conductivity and stability of nanofluids have posed the biggest challenges to their adoption as coolants in thermal applications in industries such as electronic equipment, heat exchangers, and solar technologies. In this paper, the thermal conductivity coefficient of an Al$_{12}$Mg$_{17}$ nanofluid is measured by a novel beam displacement method. Besides, the stability, particle size distribution (PSD), TEM micrograph, and electrical conductivity of Al$_{12}$Mg$_{17}$ nanofluids are investigated. For the preparation of nanofluids, three different surfactants are used to disperse Al$_{12}$Mg$_{17}$ nanoparticles in DI water using two-step method. Then, dispersion stability is monitored visually and quantified using a zeta potential test. The thermal conductivity coefficient and particle size distribution are measured using two optical setups. For the purpose of evaluating the outcomes, the thermal conductivity coefficients estimated using the beam displacement method are compared with the KD2 Pro apparatus results, and the PSD findings are examined using TEM micrographs. Results demonstrate that a 1:1 ratio of CTAB and Al$_{12}$Mg$_{17}$ nanoparticles is proper for stabilizing Al$_{12}$Mg$_{17}$ nanofluid. Also, the optimum ultrasonication period is determined to be 2 hours, and the peak of particle size distribution is measured to be 154 nanometers at this time. Thermal conductivity measurements show that the thermal conductivity coefficients improve as the concentration of Al$_{12}$Mg$_{17}$ nanoparticles increases, reaching a maximum enhancement of 40% in comparison to the base fluid at a concentration of 0.05 vol.%.