Self combustion synthesis of Al2O3 nanoparticles from bauxite utilizing sugar as fuel for nanofluids with enhanced CHF

Abstract

Nanofluids have big potential to replace conventional coolant such as water. Nanoparticles of Al2O3 for nanofluids has been successfully synthesized using self combustion method using sugar as fuel. Al(OH)3 was used as precursor. It was extracted from local bauxite. The combustion was performed at 450°C. The combusted material was calcined at 1200°C for 1 hour to get Al2O3 nanoparticles. The Al2O3 nanoparticles were dispersed into an amount of water as base fluid to form nanofluids. XRD analysis revealed that the Al2O3 nanoparticles crystallized in theta phase with crystallite size of 15.5 nm. According to TEM analyses, the particle size was 30 nm. The nanofluid with concentration of 0.025 vol % and pH 10 possessed zeta potential of -45 mV indicating a stable suspension. Compared to water as base fluid, the nanofluid prepared in this study had a CHF enhancement of 70% making the nanofluids are potential for cooling fluids of metal machining, quenching, Reactor Vessel Cooling System (RVCS), and Emergency Core Cooling System (ECCS).