Experimental analysis of the thermophysical properties of polyethylene glycol with MgO nanoparticles: Insights into thermal analysis, density, viscosity and isobaric heat capacity

• Two classes of MgO nanoparticles enhanced polyethylene glycol fluids were produced in concentrations up to 2.5 %wt. • The density of all prepared samples was experimentally measured and analyzed. • Samples viscosities were evaluated and compared against established theoretical correlations. • Viscosity hysteresis behavior was examined. • The isobaric heat capacity of the samples was discussed in relation to existing literature. Polyethylene glycol can be explored as a possible heat transfer fluid and this study scrutinizes the thermophysical properties of two classes of nanofluids based on PEG 200 and a mixture of PEG 200 and PEG 400, enhanced with 0.5–2.5 wt% MgO nanoparticles. Firstly, some insights into base fluids properties, as well as thermal analysis is discussed in comparison with state of the art. Furthermore, key thermophysical properties, like viscosity, density, and isobaric heat capacity, were measured at ambient temperature, during heating, and after multiple heating–cooling cycles to assess these new fluids temperature dependence properties and their long-term stability. Experimental results were compared with theoretical models and state of the art literature data to validate findings and explain these nanofluids performance. The results offer insights for designing advanced heat transfer fluids with applications in electronics cooling, solar energy, and industrial processes. Concluding, PEG based nanofluids can be an option for medium temperature heat transfer fluids, while this study proposes a new PEG mixture as a possible candidate. We need to underlie here that these results are part of an ongoing complex experimental work.