Study On The Flow Characteristics Of Ionic Liquid Aqueous Solution In Microtube

The investigations of fluid flow characteristics in stainless steel mircotubes are essential for the development of microchemical system, as stainless steel mircotubes are important components of microchemical system. There are relatively few investigations of electroviscous effects on fluids flow in microtubes. Ionic liquids(ILs), as an alternative to volatile organic compounds(VOCs), have promising application prospects. In order to realize the industrial application of ILs in the design of microreactor or development of micro heat exchanger, it is of great significance to study the flow characteristic of ionic liquid solution in microtubes.The main works in the paper can be summarized as following:(1) The density ρ (288.15-318.15K) and viscosity η (288.15-318.15K) of aqueous solutions of [bmim]Cl and NaNO3have been measured at atmosphere pressure. The similar-Arrhenius equation was used to relate the viscosity of aqueous solutions of [bmim]Cl and NaNO3, respectively. The correlation effect was satisfactory.(2) A device for investigating the flow characteristic and electrokinetic parameters of fluids in microtubes was designed. Not only flow pressure drop but also streaming potential caused by electrical double layer in microtubes for solutions contained ions can be measured.(3) An experiment device for investigating flow characteristic of fluids in micrtubes was designed and set up. With deionized water,[bmim]Cl and NaNO3aqueous solution as main working fluids, the experiments of flow characteristic were carried out in stainless steel microtubes with inner diameter of127.5.254.0and353.2micron. The Reynolds number varied from15-660. The effect of electroviscous on fluid flow was investigated. It is observed that there was no obvious electroviscous effects and the flow characteristics of fluids were in line with conventional behaviors in the region of those dimensions and Reynolds number range tested. What’s more, the flow characteristics of [bmim]Cl aqueous solution agreed with that of NaNO3aqueous solution.(4) The structures of eight kinds of ILs (three kinds of cations and five kinds of anions) were optimized through Chem3D and Gaussian03softwares to obtain the most stable configuration with minimum energy. The interaction energy of ILs were calculated in optimal configuration, and then related to the experimental viscosity of ionic liquids. Simulation results show that the bigger the interaction energy of ILs is, the smaller the viscosity of ILs is. In addition, the interaction energy of ILs decreases with increasing alkyl chain on cation of ILs, while the viscosity of ILs increases with increasing alkyl chain.