极性侧链离子液体的内部与表面微观结构及动力学性质的计算模拟研究

离子液体在能源、化工、军事、汽车工业等诸多领域有着广泛且重要的潜在应用。目前为止的基础研究主要针对阳离子侧链为非极性的离子液体，其中最为重要的工作之一为我们之前发现的该类离子液体的纳米尺度非均质结构，即阴离子与阳离子头部组成连续的极性网络，而阳离子侧链聚集形成不连续的非极性团簇。然而当阳离子侧链为极性时，侧链组成的非极性团簇很可能不复存在。我们拟用分子动力学模拟方法研究具有极性侧链的离子液体在纳米尺度的微观结构和动力学性质，及其对离子液体物性的影响。另一方面，离子液体表面的微观结构和动力学性质对于诸如界面催化等应用具有重要影响。我们拟首先发展针对水表面的与实验可定量比较的、基于分子动力学模拟数据的和频产生光谱计算方法，并将该方法应用于对离子液体表面的微观结构和动力学性质的研究。

Ionic liquids have wide and important potential applications in many fields, such as energy, chemical engineering, military, and automobile industry. Until now most basic researches concentrate on ionic liquids with a nonpolar cationic side chain. One of the most important discoveries is the nanoscale heterogeneity in such kind of ionic liquids, in which anions and cationic head groups form continuous polar network, while cationic side chains aggregate to form segregated nonpolar domains. However, the nonpolar domains might not exist for ionic liquids with polar side chains. We propose to study the nanoscale microscopic structure and dynamics of ionic liquids with polar side chains and their influence on the physical properties of ionic liquids. In addition, since the microscopic structure and dynamics of the surface of ionic liquids are important to their applications, such as interfacial catalysis, we also plan to study the surface of ionic liquids by means of sum frequency generation (SFG) methods based on the data obtained from molecular dynamics simulations. We will first develop the SFG calculation method for water surface, and then apply the method to ionic liquid surfaces.