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

土壤和沉积物中的坡缕石和海泡石由于其形成环境的限制而被广泛用作古环境指标。此外，它们的物理性质（特别是它们的吸附能力和催化行为）导致它们作为吸附剂广泛的工业和环境用途。 在Meigs-Attendum gas-昆西地区（这些粘土的一个重要来源）的样品中，已确定坡缕石-海泡石向蒙皂石的物理化学转化。 由于这种转变可以大大影响使用的坡缕石，海泡石作为工业吸附剂，拟议的项目调查的坡缕石，海泡石蒙皂石转化及其影响的类型和分布的活性表面位点和变化的微织物。 利用透射电子显微镜（TEM）和原子力显微镜（AFM）研究了产自Meigs-Attenugas-昆西地区的天然坡缕石-海泡石-蒙皂石组合的微组构、形貌和表面微形貌，并利用同步辐射X射线衍射和TEM数据研究了坡缕石-海泡石的体相结构。原子模型的体积和表面结构的palygorite，海泡石，特别是过渡形式将开发从TEM，X-射线和AFM数据。本研究的目的是获得一步一步的理解的转变，并模拟吸附行为的变化。 这些结果对环境（例如，重金属吸附）和商业应用（例如，油的漂白剂和澄清剂）以及利用蚀变岩相指示古环境信息的潜在能力。

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.