(489i) The Formation and Regulation Mechanism of Meso-Structure of Ionic Liquids

Ionic liquids (ILs) have been studied extensively as green solvents, catalysts and electrolytes due to their unique properties and great potentials in industry applications. However, the lack of knowledge on the formation and regulation mechanism of meso-structure in ionic liquid systems may lead to possible failure and difficulties in the new reactor and process design. Focusing on the meso-science of ILs, the following research has been conducted. We firstly discovered that H-bond in ILs showed the co-valent feature by density functional theory method and far-IR spectra. Based on the special features in molecular structure, interaction energy, electronic, dynamics and spectroscopic, the special H-bond was defined as a new concept: Z-bond.­¹ The new force fields including Z-bond model has been developed. The ionic clusters in ILs or IL mixtures at nano-level have been proved by molecular dynamic simulation and experimental characteristic. Angstrom Aggregates (AA) in IL systems with the specific size at angstrom scale might possess unique structure-activity relationship, which may benefit in the area of chemical reaction, separation, and electrochemistry. Focusing on the AA in IL systems, we discovered that Z-bond is one of the most important interactions for the formation of AA in ILs.² As important properties for scaling up a process, the gas bubble behavior in IL system, such as bubble size distribution, gas holdup, Sauter diameter were investigated, and then the mass transfer properties were measured and predicted. The methodology of IL-based process design was proposed and applied to develop several novel technologies³, such as the clean technology of dimethyl carbonate, the efficiently catalytic alkylation process, SO₂ recovery, and a green spinning process from wool keratin.