石墨氧化过程中的晶体化学特征与变化机理

The structural layer of graphite is the thinnest two-dimensional nanostructure unit in minerals. Treated by oxidation, the composition, structure and physicochemical properties of graphite oxide (GO) could be affected by the oxidation process and oxidation degree. Due to the excellent properties and wide applications of GO, the mineralogical characteristics of the graphite samples with different genetic types (the weathering and alteration zones) will be studied. In addition, the variation of the compositions, structures and properties of GO in the controlled oxidation process will be further discussed. Various modern analytical techniques and methods will be applied to characterize the compositions, structures and properties of graphite and GO samples. Besides, the activation energy and the distribution of the different oxygen containing functional groups in the inner layer and the edge will be calculated by using the first principles methods. This project aims at the investigation of the mineralogical characteristics of graphite from different areas and with different weathering degrees, and the investigation of influence of origin place and the weathering degrees on the composition, structure and properties of GO in the process of controlled oxidation. The GO with only hydroxyl or epoxy or both of the hydroxyl and epoxy groups will be prepared, and the variations and effects of oxidation degrees and oxidation conditions on the compositions, structures and properties of GO could also be revealed. The occupations and distributions of functional groups and the structural order in the natural GO and the prepared GO samples will be investigated. Moreover, the dynamics process of structure variation in the controllable oxidation process and the generation mechanism of high cation exchange capacity in hydroxyl type graphite oxide will be identified. The ideal structure models and evolution models of the three-dimensional structure of GO in the controllable oxidation process will be established.

基于石墨的层状结构和可氧化性，氧化过程和程度对产物成分、结构和理化性能的影响，石墨氧化物（GO）的优异性能和广泛用途，研究不同成因类型典型矿床（包括在风化/蚀变带中）石墨的矿物学特征及在可控氧化过程中GO的成分、结构和性能的变化规律；采用现代分析测试技术对石墨和GO样品的成分、结构和性能进行表征；采用第一性原理方法计算模拟石墨结构层内部和边缘处接入不同含氧官能团的活化能及其占位分布；查明不同产地、不同风化蚀变程度石墨的矿物学特征及其对可控氧化过程中产物的成分、结构和性能的影响；实现羟基型、环氧型及混合型GO的可控制备，揭示氧化程度与条件对GO成分、结构和性能的影响及规律性；查明天然GO及可控制备的样品中含氧官能团在结构层占位、分布及结构有序性；揭示石墨在氧化作用过程中结构变化的分子动力学机制及羟基型GO产生高阳离子交换容量的本质；建立石墨氧化过程中三维结构的演化模型及GO的理想结构模型。

基于石墨的层状结构和可氧化性，氧化过程和程度对产物成分、结构和理化性能的影响，以及石墨氧化物（GO）的优异性能和广泛用途。研究了不同成因类型典型矿床（包括在风化/蚀变带中）石墨样品的矿物学特征及在可控氧化过程中GO的成分、结构和性能的变化规律；采用多种现代分析测试技术对石墨和GO样品的成分、结构和性能进行表征；采用第一性原理方法计算模拟石墨结构层内部和边缘处接入不同含氧官能团的活化能及其占位分布。.查明了不同成因类型石墨的矿物学特征及在风化蚀变带中石墨含氧量和官能团类型的变化，确认了天然GO的存在、晶体化学分类位置及野外赋存状态；揭示了不同成因类型石墨在不同氧化条件下羟基型、环氧型及混合型GO成分、结构、谱学参数及理化性能（如导电性、表面电性、阳离子交换性、气体敏感选择性）之间的关系，实现不同含氧官能团类型和含量GO的可控制备；查明了天然石墨氧化物及可控制备的GO样品中含氧官能团在结构层占位、分布及结构有序程度等，揭示了碳原子杂化方式由sp2转变为sp3过程中结构体系能量变化及sp2平面域的变化规律；建立了石墨在氧化作用过程中三维结构的演化模型，建立羟基型、环氧型及混合型GO的理想结构模型；揭示羟基型GO高阳离子交换容量产生的本质。.所获得的成果填补了近年来石墨矿物学研究的不足，为石墨的矿物学和应用开发及系列功能化石墨烯材料制备和应用奠定了良好的理论和实验工艺技术基础；对氧化－还原法制备石墨烯材料及应用推广具有重要的借鉴意义。