Collaborative Research: The Palygorskite-Sepiolite to Smectite Transformation and the Influence on Reactive Surface Sites

合作研究：坡缕石-海泡石向蒙皂石的转变及其对反应表面位点的影响

• 批准号: 0001251
• 负责人: John Rakovan
• 金额: $ 2.7万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0001251&HistoricalAwards=false
• 关键词: Collaborative; Research; Palygorskite; Sepiolite; Smectite

RakovanEAR-0001251The presence of palygorskite and sepiolite in soils and sediments is widely used as a paleoenvironmental indicator because of their restricted environments of formation. In addition, their physical properties (especially their sorption capacity and catalytic behavior) has lead to their extensive industrial and environmental use as sorbants. The physiochemical transformation of palygorskite-sepiolite to smectite has been identified in samples from the Meigs-Attapulgas-Quincy district, an important source of these clays. Because this transformation can considerably affect the use of the palygorskite-sepiolite as industrial sorbants, the proposed project investigates the palygorskite-sepiolite to smectite transformation and its influence on the type and distribution of reactive surface sites and changes in micro-fabrics. The micro-fabric, morphology, and surface micro-topography of a natural palygorskite-sepiolite-smectite assemblage from the Meigs-Attapulgas-Quincy district will be studied using transmission electron microscopy (TEM) and atomic force microscopy (AFM), and the bulk structure of palygorskite-sepiolite will be studied using synchrotron X-ray diffraction and TEM data. Atomic models of the bulk and surface structures of palygorskite, sepiolite, and especially transitional forms will be developed from the TEM, X-ray, and AFM data. The purpose of this study is to obtain a step-by-step understanding of the transformation and to model the variation in sorption behavior. The results are important for environmental (e.g., heavy-metal adsorption) and commercial applications (e.g., bleaching and clarifying agents of oils) as well as the potential ability to use altered lithofacies to indicate paleoenvironmental information.

RakovanEAR-0001251由于坡缕石和海泡石的形成环境受到限制，土壤和沉积物中存在的坡缕石和海泡石被广泛用作古环境指标。此外，它们的物理特性（特别是吸附能力和催化行为）导致它们作为吸附剂在工业和环境中广泛使用。 在来自梅格斯-阿塔普尔加斯-昆西地区（这些粘土的重要来源）的样品中已经鉴定出凹凸棒石-海泡石向蒙皂石的物理化学转化。 由于这种转变会极大地影响坡缕石-海泡石作为工业吸附剂的使用，因此该项目研究了坡缕石-海泡石向蒙皂石的转变及其对反应表面位点的类型和分布以及微织物变化的影响。 将使用透射电子显微镜 (TEM) 和原子力显微镜 (AFM) 研究来自 Meigs-Attapulgas-Quincy 地区的天然凹凸棒石-海泡石-蒙脱石组合的微结构、形态和表面微形貌，并且将使用透射电子显微镜 (TEM) 和原子力显微镜 (AFM) 研究将使用同步加速器 X 射线衍射和 TEM 数据研究坡缕石-海泡石的结构。坡缕石、海泡石，特别是过渡形式的本体和表面结构的原子模型将根据 TEM、X 射线和 AFM 数据开发。本研究的目的是逐步了解转变并模拟吸附行为的变化。 这些结果对于环境（例如，重金属吸附）和商业应用（例如，石油的漂白和澄清剂）以及利用改变的岩相来指示古环境信息的潜在能力非常重要。