Ionic Liquids of Improved Thermal Stability

在这个由化学学部化学结构、动力学和机理B项目资助的项目中，南阿拉巴马大学化学系的James Davis教授和他的学生将探索一种新型离子液体（液体盐）的合成、表征和性能。所研究的液体盐应具有高度的耐热性，并能长时间保持其液体特性，不蒸发、不分解、不可燃性。原则上，这种类型的盐可以用作更传统液体的替代品，应用范围从传热流体和高性能润滑剂到生物质加工和重要电子材料（如半导体）的合成。该项目汇集了化学合成以及材料科学和工程的元素，并为参与的学生提供了从一系列活动中获得经验的广泛机会。由于将进行研究的机构为来自科学和工程领域代表性不足的群体的很大比例的个人提供服务，因此本项目将提供重要的机会，参与对来自这些社区的个人的专业培训。离子液体是一种具有重要基础价值和日益增长的实用价值的材料。由于其不挥发性，离子液体可用于需要高温的应用，例如传热，润滑或高温材料合成。虽然典型的ILs具有相对较高的热稳定性，但它们仍然无法在200摄氏度以上的温度下长时间使用。在本项目中，将使用四苯基磷阳离子及其衍生物制备il。初步研究表明，前一种阳离子在超过300摄氏度的温度下可以稳定几天而不会分解或蒸发。在这些发现的基础上，热分解最终发生的机制将被研究，这些知识将被用来制造更高热稳定性的盐。除了创造高热稳定性的新型熔盐外，这些液体还将用于促进生物质的快速热解（用于生产生物油）以及电子重要材料（如ZnS和CdSe）的热合成。

In this project, funded by the Chemical Structure, Dynamics and Mechanism B Program of the Chemistry Division, Professor James Davis and his students of the Department of Chemistry at the University of South Alabama will explore the synthesis, characterization, and properties of a new type of ionic liquids (liquid salts). The liquid salts to be investigated are expected to be highly resistant to heat and to retain their liquid character, without evaporation, decomposition, or flammability, for long periods of time. Salts of this type can, in principle, be used as substitutes for more traditional liquids in applications ranging from heat transfer fluids and high-performance lubricants to biomass processing and the synthesis of important electronic materials such as semiconductors. The project brings together elements of chemical synthesis as well as material science and engineering, and offers engaged students a broad opportunity for gaining experience from a spectrum of activities. Since the institution at which the research will take place serves a high proportion of individuals from groups underrepresented in the sciences and engineering, the present project will provide important opportunities to engage in the professional training of individuals from these communities.Ionic liquids (ILs) are materials of considerable fundamental interest and growing practical utility. Because of their non-volatility, ionic liquids can be used in applications requiring high temperatures, such as in heat transfer, lubrication, or high-temperature materials synthesis. Although typical ILs have relatively high degrees of thermal stability, they are still incapable of being used for long durations at temperatures above 200 degrees Celsius. In the present project, ILs will be prepared using the tetraphenylphosphonium cation and derivatives thereof. Preliminary work has revealed that the former cation is stable to temperatures in excess of 300 degrees Celsius for days without decomposition or evaporation. Building on these findings, the mechanism by which thermal decomposition eventually does occur will be studied, and that knowledge will be harnessed to create salts of still higher thermal stability. In addition to creating new molten salts of high thermal stability, the use of these liquids in facilitating the rapid pyrolysis of biomass (for production of bio-oil) and in the thermal synthesis of electronically important materials such as ZnS and CdSe will be investigated.