Thermal Conductivity Enhancement of Aqueous Ionic Liquid and Nanoparticle Suspension

Abstract

In the present study, the thermal conductivities of ionic liquid + water in the concentrations 0.1-0.6 %w/w and temperatures (302.5-337.9 K) are determined. The thermal conductivity of aqueous 1-butyl-3-methylimidazolium bromide declined with increasing concentration and temperature. A quadratic model is developed for predicting the thermal conductivity of aqueous ionic liquid using response surface methodology with R 2 = 0.99. A two-layered feed forward back propagation neural network 2-10-1 is also modeled with mean square error, root means square and absolute average error percentage of 0.005, 0.071 and 2.684, respectively. The thermal conductivity of nanofluid (γ-Al 2 O 3 /water) is estimated and compared with the ionic liquid solution at the same concentration and temperature range. Thermal conductivity enhancement ratios of aqueous ionic liquids are found to be more than nanoparticle suspensions.

Thermophysical and tribological behaviors of multiwalled carbon nanotubes used as nanolubricant additives

“…Nanoparticles have strong van der Waals bonds that cause them to form nanoclusters, which lead to a rich zone of high thermal conductive nanoparticles that improve the fluid's bulk thermal conductivity [78]. Figure 9 shows that the thermal conductivity trends of the engine oil and nanolubricant decreased with the increase in temperature [19,[79][80][81][82][83]. Since the vibrational motion of electrons and phonons is increased as temperature rises, the thermal conductivity of a metal is expected to rise.…”

Thermal Conductivities of NTf2-Based Ionic Liquids: Experimental Measurement and Prediction via Group Contribution Methods

“…While thermal conductivity is a macroproperty, it can also help provide a greater understanding of the IL on a molecular level since it can provide insight into the relative lattice energies, give more insight into its packing structure, and an estimate of the mean free path of a molecule. 20 In comparison to solids, the measurement of the thermal conductivity of fluids presents more challenges. This is due to the tendency of an external temperature gradient to induce convective heat transfer as a result of the bulk movement of fluid.…”

“…For example, the thermal conductivity of water is 0.58 W·m –1 ·K –1 , while those of benzene and methanol are around 0.15 and 0.20 W·m –1 ·K –1 , respectively. While thermal conductivity is a macroproperty, it can also help provide a greater understanding of the IL on a molecular level since it can provide insight into the relative lattice energies, give more insight into its packing structure, and an estimate of the mean free path of a molecule …”