This study used various approaches to create various nanofluids (NFs) by combining a molten salt mixture (60% calcium nitrate (Ca(NO₃)₂) – 40% lithium nitrate (LiNO₃)) with 2 wt.% of copper oxide (CuO)-titanium dioxide (TiO₂) nanoparticles (NPs). Concentrated solar plants can use these NFs as thermal energy storage (TES) materials by increasing the base fluid’s thermal properties, which reduces the amount of storage material required. The goal of introducing new mixing processes that do not include sonication was to eliminate this stage, which could be impractical for large-scale productions, and to enable the production of a higher amount of NF. A magnetic stirrer, together with two mechanical mixers, were utilized for this specific task. A 150 g/L concentration of each NF was used to make the aqueous solution. Additionally, the most effective mixer was used to investigate the effects of different concentrations (350 and 550 g/L). To determine the specific heat, latent heat, and melting point differential scanning calorimetry (DSC) was employed. Furthermore, we measured the thermal conductivity and diffusivity of the solid-state. The specific heat increased by 32% in the solid and 16% in the liquid phase when 150 g/L was used with both mechanical mixers, according to the data. The same NFs exhibited a greater capacity to store heat as well. High solution concentrations (up to 26% and 48%, respectively) were similarly associated with an increase in thermal conductivity and diffusivity. This was particularly true for the NFs with the greatest increases in thermal properties; furthermore, they found that the best distribution of NPs was achieved at the lowest concentrations. In highly concentrated water solutions, NFs with improved thermal characteristics can be efficiently and cheaply produced utilizing mechanical mixers.

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