Experimental studies on thermal conductivity and heat transfer of 1-Butyl-3-methylimidazolium tetrafluoroborate ionic liquid and its nanocolloids

Abstract

This paper outlines and discusses the thermal conductivity of 1-Butyl-3-methylimidazolium tetrafluoroborate ionic liquid, as well as three classes of nanocolloids. The [C4mim][BF4] ionic liquid was enhanced with three kinds of nanoparticles, Al2O3, ZnO and MWCNT and all fluids thermal conductivity was experimentally measured. Results discussion includes also an in-depth analysis on Prandtl number and thermal diffusivity. All the data were carefully debated in terms of state of the art advancement and these suspensions suitability for practical applications in heat transfer. It was found that the thermal conductivity increases with nanoparticles addition and this enhancement depends on nanoparticle type and temperature. Plus, the temperature influence is rather limited, while the consideration on Prandtl number and thermal diffusivity revealed that it is extremely relevant to consider all the thermophysical properties when choosing a new thermal fluid. Additionally, a comparison with well known correlations was inserted, concluding that no theory can estimate the ionic liquids nanocolloids thermal conductivity. Concluding, the thermal properties of [C4mim][BF4] ionic liquid and its nanocolloids with Al2O3, ZnO and MWCNT shows that these nanocolloids uncover great potential for heat transfer applications.