Site Specific Energetics of Water in Rock-Forming Zeolites

NeuhoffEAR-0336906含分子水矿物是地壳浅层的重要相态。这些矿物的稳定性的定量模型对于预测它们在地球整体地球化学行为中的作用是必要的；然而，分子水容易进入和离开这些矿物的事实使这种模型变得复杂。这项研究项目通过实验测定水化和脱水对沸石稳定性的影响来解决这一难题，沸石是最丰富的含水矿物之一。这是通过直接观察沸石的水分含量作为温度和湿度的函数，以及直接测量这些矿物在水化和脱水时消耗或产生的热量来实现的。拟议研究的更广泛影响包括由研究生和本科生直接参与的综合研究和教育经验，他们将接受现代实验方法和热力学分析方面的培训和经验。此外，拟议研究的方法还将用于开发创新的课堂练习，让学生在P.I.S物理地球化学课程中亲身体验热化学方法。研究产生的数据不仅将作为国际学术期刊发表，还将在互联网上免费下载，从而为科学基础设施做出贡献。由此产生的数据不仅将应用于地球化学，还将应用于材料科学(沸石是重要的催化剂和吸附材料)。

NeuhoffEAR-0336906Minerals containing molecular water are important phases at shallow levels in Earth's crust. Quantitative models of the stability of these minerals are necessary for predicting their role in the overall geochemical behavior of the earth; however, the fact that molecular water readily enters and leaves these minerals complicates such models. This research project addresses this difficulty through experimental determination of the effects of hydration and dehydration on the stability of zeolites, which are one of the most abundant types of water-bearing minerals. This is accomplished through direct observations of the water content of zeolites as a function of temperature and humidity, and direct measurements of the heat consumed or produced as these minerals hydrate and dehydrate. Broader impacts of the proposed study include integrated research and educational experiences derived from the direct involvement of graduate and undergraduate students, who will receive training and experience in modern experimental methods and thermodynamic analysis. In addition, the methods of the proposed study will be used to develop innovative classroom exercises to give students hands-on experience in thermochemical methods in the P.I.'s physical geochemistry course. Data generated in the study will be disseminated not only as publications in international scholarly journals, but will also be available for free download on the Internet, thereby contributing to the infrastructure of science. The resultant data will have application not only in geochemistry, but also in materials science (where zeolites are important catalysts and sorbent materials).