Experimental Study on Electrical Conductivity of Several [C4mim][BF4] Ionic-Liquid-Based Nanocolloids

Nanocolloids are receiving considerable attention in regard to their properties and future applications, especially as heat transfer fluids and phase change materials for energy storage. Additionally, studies on ionic liquids and ionic-liquid-based nanocolloids are at the forefront of research preoccupations. This study aims to shed light on applications of nanocolloids based on [C4mim][BF4] ionic liquid, giving insight into the electrical conductivity of [C4mim][BF4] ionic liquid, as well as three types of nanoparticles suspended in this particular ionic liquid, namely Al₂O₃ (alumina), ZnO (zinc oxide) and MWCNT (multi-walled carbon nanotubes). In this experimental research, three types of suspensions were carefully prepared and the electrical conductivity was measured both at ambient temperature and during heating. The results are discussed in the context of the state of the art. The electrical conductivity variation with temperature was found to be linear, and nanoparticle loading significantly influenced the electrical conductivity of the suspensions. A complex analysis in terms of temperature and nanoparticle type and loading was performed. In conclusion, the electrical properties are relevant for many applications and further experimental work needs to be devoted to their study.