文摘
Room-temperature ionic liquids (ILs) which are regarded as environmentally benign solvents are widely used in many research areas. However, the purity of ILs influences the properties of ILs and further applications. The remains of water and organic solvents in ILs not only reduce the purity of ILs but also influence the physicochemical properties and even the results of reactions performed in ILs. In this work, we found a new method, sweeping solvents by N2, to remove quickly the volatile impurity in ILs at mild conditions. The effecting factors of the new method and the comparison with the traditional method have been investigated, and it was found that temperature and N2 flow rate influence the time for removing volatile impurities from four types of ILs. The new method can easily remove the IL’s impurities, including water, ethanol, methanol, acetonitrile, ethyl acetate, and acetone, to a mass fraction as low as 10−3, and the time decreases greatly to just a few hours, even less than 0.5 h. Furthermore, the mechanism of sweeping solvents by blowing N2 has been investigated.