A critical review on thermophysical and electrochemical properties of Ionanofluids (nanoparticles dispersed in ionic liquids) and their applications

The problems associated with the ever-increasing energy consumption have urged researchers to develop systems that contain renewable, sustainable, and green synthesis operations. Nanotechnology as an applied field has evolved in numerous areas with multiple directions during recent decades. Nanotechnology utility in ionic liquids has helped introduce a new class of liquids formally known as Ionanofluids (INFs). INFs belong to an indigenous class of nanofluids possessing extraordinary enhancement in thermophysical and electrochemical properties. This study summarizes the synthesis of INFs, influence of temperature and nanoparticles concentration of INFs in terms of thermophysical and electrochemical properties, before enlisting wide applications related to these properties such as solar thermal utilization, electrolytes, lubrication, catalysis, and separation processes. The key focus of this article is to address parameters such as thermal and electrical conductivity, (specific) heat capacity, viscosity, and density as a result of the temperature variation, different mass loadings of nanoparticles and the ionic liquid nature. A comparison is drawn between different INFs on the basis of their combination and composition. Moreover, this study also enlists the reasons behind their proposed applications. Future challenges and hurdles associated with INFs, especially stability, cost, and mass production issue of INFs are also addressed.