Thermophysical evaluation of PEG 200/400 binary nanocolloids containing MgO nanoparticles: an experimental approach

Abstract This study introduces a novel equimolar PEG 200–PEG 400 binary base fluid designed to combine the advantages of both polymers, while MgO nanoparticles were incorporated at varying concentrations to further improve its thermal performance. The work presents a rigorous experimental characterization of the resulting nanocolloids, measuring and discussing density, isobaric heat capacity, and viscosity. Comparative analysis in terms of base fluids and nanocolloids reveals that nanoparticle integration increases density while inducing a moderate viscosity increase in low-concentration samples at ambient temperatures. Crucially, isobaric heat capacity exhibited a distinct sensitivity to both temperature and nanoparticle loading, prompting the development of new empirical correlation equations. Additionally, an investigation into viscosity hysteresis confirms that MgO nanoparticles significantly influence the fluid’s internal friction. These findings advance the development of PEG-based nanocolloids for advanced thermal management systems. The data analysis and proposed correlations suggest that the MgO-PEG interactions may influence the energy transport mechanisms within the liquid phase. Overall, the present experimental results may provide a useful basis for further investigating and potentially tailoring the thermal behavior of PEG-based nanocolloids for heat-transfer applications.