Conventional heat transfer fluids such as water are widely utilized in thermal systems due to their availability and low cost, yet their efficiency is limited by relatively low thermal conductivity. To address this, nanofluids have emerged as a promising solution. However, their practical application is often hindered by poor dispersion stability, particle agglomeration, sedimentation and increased viscosity, which can negatively impact long-term operation and pumping requirements. This study investigates the formulation and thermophysical properties of magnesium oxide (MgO)-water nanofluids stabilized using polyvinylpyrrolidone (PVP). Nanofluids with concentrations ranging from 0.2 to 1.0 wt% were prepared using a two-step method involving homogenization and ultrasonication. Stability was assessed through visual observation as a preliminary assessment. TWhermal conductivity and viscosity were measured, while density and specific heat capacity were theoretically estimated for heat transfer suitability. The results indicate that the incorporation of MgO nanoparticles enhances thermal conductivity, with values increasing from 0.600 W/mK for water to 0.639 W/mK at 1.0 wt%. Temperature-dependent analysis further shows improvement up to 0.664 W/mK at 50°C. Although viscosity increases with concentration, the increase remained moderate under the tested measurement conditions. Among the tested formulations, 0.2 wt% exhibits the most favourable balance between stability and thermophysical performance. The results indicate that the use of PVP is associated with improved short-term dispersion behaviour in MgO-water nanofluids under the present preparation conditions. The findings suggest that PVP-stabilized MgO nanofluids show potential for thermal management applications, although further quantitative stability characterization is required.
Rafaizul et al. (Thu,) studied this question.