Ionanofluids Based on Ionic Liquid Mixtures, a New Approach as an Alternative Material for Solar Energy Storage

Hybrid materials based on ionic liquids (ILs) known as Ionanofluids (INFs) have shown exciting improvements in their thermophysical properties compared to their base fluids (BF). Within this group, INFs obtained using mixtures of ionic liquids as BFs have been virtually ignored until now. In this work, INFs composed of two equimolar mixtures of ILs, [Omim][PF6] + [Odmim][PF6] and [Omim][PF6] + [Odmim][BF4] as base fluids and Multiwalled Carbon Nanotubes (MWCNTs) with weight percentages of 0.04, 0.06, 0.08, and 0.1 wt% were elaborated. Furthermore, the thermophysical properties of our proposed new materials were evaluated and compared to conventional materials currently used in solar energy storage systems. It was shown that the heat capacity (Cp) reaches increases of up to 3.7 and 3.2 times that of nitrated salts and the commercial fluid Therminol VP-1, which translates into a 9.4% and 284% higher thermal storage density (E), respectively, and even lower thermal diffusivity (α), which supports the preliminary idea of using these new materials for energy storage. © 2022 Elsevier B.V.