Ion exchange synthesis and thermal characteristics of some $\left[ \rm{\mathbf{N}}_{{2222}}^{{+}} \right]$ based ionic liquids

Abstract

Eight salts were obtained by reacting tetraethylammonium cation $\big[ {{\rm {\bf N}}_{{\rm {\bf 2222}}}^{{+}} } \big]$ with inorganic anions like BF $_{{4}}^{{-}}$ , NO $_{{3}}^{{-}}$ , NO $_{{2}}^{{{-}}}$ , SCN − , BrO $_{{3}}^{{-}}$ , IO $_{{3}}^{{-}}$ , PF $_{{6}}^{{-}}$ and HCO $_{{3}}^{{-}}$ using ion exchange method. These ionic liquids (ILs) were characterized using thermal methods, infrared spectroscopy and densitometry. Thermophysical properties such as density, coefficient of volume expansion, heat of fusion, heat capacity and thermal energy storage capacity were determined. Thermal conductivity of the samples was determined both in solid and liquid phases. Owing to high values of thermal energy storage capacity coupled with handsome liquid phase thermal conductivity, ILs under investigation were recommended as materials for thermal energy storage (TES) as well as heat transfer applications.