GOALI: Design and Evaluation of Room Temperature Ionic Liquids for Green Chemical Processing

圣母大学布伦内克分校生产的离子液体(ILS)是一种在常温下处于纯净状态的液体的有机盐。典型的离子液体是由体积较大的吡啶或咪唑阳离子与多种阴离子配对而成。分子的体积和不对称性阻止了促进结晶的容易堆积，因此这些材料表现出低熔点。尽管ILS是有机溶剂，但它们呈现出消失的小蒸汽压，因此没有最普遍的逃逸到大气中和接触到工人的途径--蒸发。低蒸汽压也使这些溶剂更安全，因为闪点将比传统有机溶剂高得多。研究表明，离子液体是各种工业上相关反应的极佳溶剂。然而，由于缺乏有关离子液体的物理性质和相行为的文献数据，离子液体的使用受到限制。即使是基于1-甲基咪唑的简单离子液体结构上的排列数目也非常多，结构和性能之间的相关性目前还不存在。当前的目标是探索离子液体的化学结构与其物理性质之间的关系，包括它与二氧化碳、其他小分子、水和有机溶质的相行为。其方法是结合实验测量使用分子模拟来开发结构/性质关系，这些关系可用于指导设计和所需的性质。特别是，我们提出了合成各种咪唑基离子液体，并测量了它们的纯组分熔点和密度。建议为蒙特卡罗模拟开发分子力场，以充分再现纯组分数据。建议使用几种不同的高压汽液平衡装置、重量分析技术和层析技术来测量其中一些离子液体与有机物、水、CO2和O2或H2的相行为。为了补充这些实验工作，有人建议使用Gibbs系综蒙特卡罗来模拟含有CO2或H2等小分子的离子液体的相行为。在测量和建模的基础上，我们建议建立IL结构与其物理性质和相行为之间的关系。这些信息将对评估ILS在各种重要工业应用中的应用(将在未来的项目中开发)至关重要。一些例子包括使用ILS作为反应和分离的环境友好的溶剂，作为有效的氢化、氧化和氢甲酰化化学的介质，使用二氧化碳作为安全的吸附制冷系统来取代CFCs和HFCs，作为储氢介质，以及作为聚合物凝胶纺丝的溶剂。

ABSTRACTCTS-9987627Brennecke, JoanUniversity of Notre DameIonic liquids (ILs) are organic salts that in their pure state are liquids at ambient temperature. The typical IL is based on a bulky pyridinium or imidazolium cation paired with a variety of anions. The bulkiness and asymmetry of the molecule prevents the easy packing that promotes crystallization, and hence these materials exhibit low melting points. Although ILs are organic solvents, they exhibit vanishing small vapor pressures, and thus the most prevalent route for escape to the atmosphere and also exposure to workers -- evaporation -- is absent. Low vapor pressure also renders these solvents safer, as flash points will be much higher than for traditional organic solvents. Research has shown that ILs are excellent solvents for a variety of industrially relevant reactions. However, the use of ILs is limited by the paucity of literature data on their physical properties and phase behavior. The number of permutations on the structure of even simple ILs based on 1-methyl imidazolium is extremely large and correlations between structure and properties do not currently exist.The immediate goal is to explore the relationship between the chemical structure of an IL and its physical properties, including its phase behavior with CO2, other small molecules, water, and organic solutes. The methodology is to use molecular simulations in concert with experimental measurements to develop structure/property relationships that could be used to guide the design, desired properties. In particular, we propose to synthesis a variety of imidazolium-based ionic liquids and measure their pure component melting points and densities. It is proposed to develop molecular forcefields for Monte Carlo simulations that adequately reproduce the pure component data. It is proposed to measure the phase behavior of some of these ionic liquids with organics, water, CO2 and O2 or H2 using several different high pressure vapor/liquid equilibrium apparatuses, gravimetric techniques, and chromatography. To complement these experimental efforts, it is proposed to use Gibbs ensemble Monte Carlo to simulate the phase behavior of an ionic liquid with small molecules such as CO2 or H2. Base upon the measurements and modeling, we propose to develop relationships between the IL structure and its physical properties and phase behavior. This information will be vital to the evaluation of ILs for a variety of important industrial applications (to be developed in future projects. Some examples include the use of Ils as environmentally benign solvents for reactions and separations, as a medium for efficient hydrogenation, oxidation and hydroformylation chemistry, with CO2 as a safe adsorption refrigeration system to replace CFCs and HFCs, as a hydrogen storage medium, and as a solvent for the gel-spinning of polymers.