Preparation and thermophysical investigations of water and ethylene glycol based CuO nanofluid using cationic CTAB surfactant for heat transfer application

In this study, we report the synthesis of copper oxide (CuO) nanoparticles and water, ethylene glycol based nanofluid for heat transfer application. The sol-gel self-ignition technique was chosen for its ability to produce high-purity, homogeneous materials. The prepared CuO precursor underwent calcination at 550 °C to enhance crystallinity and remove organic components. A comprehensive characterization of the synthesized CuO nanoparticles were performed using multiple analytical techniques. XRD analysis shows the CuO nanoparticles with crystalline nature and revealed an average crystallite size of 19 nm, calculated using the Debye-Scherrer equation. UV–Visible spectroscopy technique was utilized to analyse the optical properties, revealed the band gap of 2.20 eV, which confirms the semiconducting nature of CuO. The FTIR spectrum of CuO shows characteristic peaks at 470 cm⁻¹ and 414 cm⁻¹ confirms the of CuO nanoparticle formation. Field Emission Scanning Electron Microscopy (FESEM) was utilized to analyse the morphology and size distribution of the nanoparticles. SEM imaging revealed grain size of 41.9 nm. To explore the potential of the synthesized CuO in thermal management applications, a nanofluid was formed by dispersing the prepared nanoparticles with CTAB surfactant of different volume fraction in deionized water and ethylene glycol. The stability of the prepared nanofluid was tested through zeta potential studies. The thermal conductivity increases with CuO volume fraction for both water and ethylene base nanofluids. CuO nanoparticles demonstrate the potential of this material for heat transfer applications, opening avenues for improved thermal management in industrial and technological applications.