The Preparations,Physicochemical Properties And Applications Of Amine-functionalized Task-specific Ionic Liquids

Ionic liquids are regarded as the ideal substitute of traditional volatile organic reagents,because of their excellent characteristics.Utilizing their characteristics of adjustable structure,functional ionic liquids containing NH2 were synthesized for improving the absorption properties of CO2 under the normal temperature and pressure.In this dissertation,a research had been made on improvement on synthesis method of functional ionic liquids containing NH2,determination of physical and chemical parameters and the absorption properties of CO2,application of quantum chemistry calculation methods on CO2 absorption.Through the optimization of reaction conditions and improvement of synthesis and purification methods,three kinds of functional ionic liquid containing NH2,which are more conducive to industrial promotion,were synthesized and analyzed for purity analysis and structure characterization.The influence of absorption temperature、absorption pressure、absorber concentrate and ionic structure to the absorption properties of CO2 were investigated.The experimental results show that three kinds of functional ionic liquid containing NH2 synthesized have better absorption performance of CO2 under the normal temperature and pressure due to chemical reaction,the absorption capacity amounts to 0.5mol·mol-1 NHa2;the absorption rich liquid of the three kinds of functional ionic liquid have good regeneration performance under the heating or reduced pressure state,simultaneously can be recycled many times without affecting the absorption performance.The mechanism of the CO2 and 1-ethylamine-3-methyl imidazolium tetrafluoroborate[NH2e-mim]BF4 was explored by means of quantum chemistry calculation.Using B3LYP method of density functional theory(DFT)at the 6-3111++G(d,p)level with Gaussian 09 program,various material structure in the[NH2e-mim]BF4-CO2 reaction system,were geometrically optimized,and the charge distribution,thermodynamic variables and vibration frequency of the related material structure were calculated.The charge characteristics,thermodynamic properties,vibration characteristics and molecular orbital of the optimal structure were analyzed,the formation and amount of hydrogen bond of ion liquids were investigated,consequently the effects on the physicochemical properties of ionic liquids by material structure were explained,reaction mechanism of[NH2e-mim]BF4 with CO2 were determined.And the transition state in reaction process of[NH2e-mim]BF4 with CO2 was found,by scanning.The densities and viscosities of three kinds of functional ionic liquids were measured at 0.1 MPa,293.15K.The results show that the densities of functional ionic liquids are slightly larger than the density of water under the same temperature,and between 1.0g·cm-3 and 1.8g·cm-3.The viscosities of them are larger than that of the conventional organic reagents,but are still the lower values in the same series.Viscosity change rules of functional ionic liquids are similar to that of general ionic liquids.The mixture densities,mixture viscosities,surface tension of MEA-C solution were measured at 0.1MPa,293.15～323.15K.The results show that the aboved physicochemical properties decrease with the increasing of temperature and the decreasing of the solution concentration.The mutual estimation between the mixture densities and the surface tension of MEA-C solution with a certain accuracy were achieved by utilizing the aboved experimental datum and the calculation and character of parachor.