Aqueous electrolytes and non-electrolytes in under sub-critical and super-critical conditions

许多地质和工业过程是在远远超出常规室温测量范围的条件下进行的。这项提议的目的是发展所需的知识库和理论知识，以描述在发电站、先进核反应堆、地热矿体、深海热液喷口和重油热开采中遇到的极端温度和压力下水体系的行为。 灵敏的流动热量计和密度计由惰性材料制成，可承受腐蚀条件，将用于在温度高达400摄氏度、压力高达350大气压的液态水中测定简单电解液和有机分子的热力学性质，以检查接近水临界点的条件下离子电荷和有机官能团的影响。化学物种的形式及其平衡常数将通过在高温、高压流动池中使用紫外可见光谱、拉曼光谱、量热、密度测量和一种独一无二的高精度电导仪器进行现场测量来确定，所有这些都能够达到亚临界或超临界条件。钻石顶锤和高压流动池将与共聚焦拉曼显微镜一起使用，通过在极端温度和压力下直接观察来检查相关系和识别主要化学物种。这些测量将产生新的热力学数据、传输性质、半经验模型和理论方法，用于预测在极端温度和压力下运行的水基工业和自然系统中水相无机和有机溶质的性质和相行为。 这项工作的新颖性在于正在研究的非常极端的条件，识别异常影响的可能性，以及开发专门的仪器技术以获得在这些非常激进的条件下复杂水体系的定量数据的必要性。

Many geological and industrial processes take place at conditions far beyond the range of conventional room temperature measurements. The objective of this proposal is to develop the knowledge base and theoretical understanding needed to describe the behaviour of aqueous systems at extremes of temperature and pressure encountered in electrical power stations, advanced nuclear reactors, geothermal ore bodies, deep-ocean hydrothermal vents, and the thermal recovery of heavy oil. Sensitive flow calorimeters and densimeters, constructed of inert materials to withstand the corrosive conditions, will be used to determine the thermodynamic properties of simple electrolytes and organic molecules in liquid water at temperatures up to 400 oC and pressures as high as 350 atmospheres, to examine the effects of ionic charge and organic functional groups under conditions approaching the critical point of water. The form of the chemical species, and their equilibrium constants, will be determined by in situ measurements in high temperature, high pressure flow cells using UV-visible spectroscopy, Raman spectroscopy, calorimetry, densimetry and a one-of-a-kind, high-precision conductance apparatus, all capable of reaching sub-critical or supercritical conditions. Diamond anvil and high pressure flow cells will be used in conjunction with confocal Raman microscopy to examine phase relations and to identify major chemical species by direct observation at extremes of temperature and pressure. These measurements will yield new thermodynamic data, transport properties, semi-empirical models, and theoretical methods for predicting the properties and phase behaviour of aqueous inorganic and organic solutes in water-based industrial and natural systems operating under extremes of temperature and pressure The novelty in the work lies in the very extreme conditions being studied, the potential for identifying unusual effects, and the need to develop specialized instrumental techniques to obtain quantitative data for complex aqueous systems under these very aggressive conditions.