纳米级管状矿物埃洛石和伊毛缟石的无溶剂纳米流体化之机理研究

The transformation from the powder of nanominerals to the solvent-free nanofluids with liquid-like behaviors has never been investigated in previous studies. However, conducting a study on this issue would be of great meaning for extending the uses of nanominerals. This project aims at systematically exploring the in-depth mechanisms concerning the transformation from two typical nanosized tubular minerals, halloysite and imogolite, to the above-mentioned solvent-free nanofluids. In particular, two key mechanism issues, i.e., how the mineralogical factors and physic-chemical conditions affect the transformation processes and ways will be focused. A comparative study on halloysite and imogolite will be conducted to clarify how the big difference of them in microstructures and the characteristics of surface groups could affect the properties of the resulting nanofluids. Through this comprehensive investigation, some firsthand information and data concerning the transformation from the nanominerals to the nanofluids as well as the composition, microstructures and properties of the obtained nanofluids will be provided. And the knowledge on the interface interactions between nanosized tubular minerals and organics will be substantially deepened. It is anticipated that the fundamental information derived from the currently proposed project is of significance both theoretically and experimentally for the future studies on surface-interface reactions of nanominerals and for mineral-based materials.

天然纳米矿物的无溶剂流体化是纳米矿物学研究中前人尚未涉足的新方向，对其开展研究探索是拓展纳米矿物相关应用的基础。本项目拟系统研究两种典型的纳米管状矿物（埃洛石和伊毛缟石）的无溶剂纳米流体化所涉机理问题，重点探明两大机制问题，即纳米矿物无溶剂流体化的关键矿物学制约机制和界面物理化学制约机制，探明影响上述矿物无溶剂流体化的主要制约因素、条件和机理，尤其是对比、揭示二者在管孔微结构和表面基团分布、特性上的显著差异如何影响其无溶剂纳米流体化过程和机理。相关工作将提供纳米管状矿物无溶剂纳米流体化反应和纳米流体成分、微观结构和性质的第一手资料和数据，同时将深化对纳米管状矿物与有机质间界面作用机制的认知，对矿物表界面学和纳米矿物学研究均具有重要意义。

天然纳米矿物的无溶剂纳米流体化是纳米矿物学研究中前人尚未涉足的新方向，对其开展研究探索是拓展纳米矿物相关应用的基础。为此，本项目以典型纳米管状矿物埃洛石和伊毛缟石以及纳米空心球状矿物水铝英石为研究对象，实现了其无溶剂纳米流体化，明确了制备的方法、条件和机理，厘清了界面作用方式、有机分子类型、纳米矿物结构和颗粒分散性以及反应体系极性等对纳米流体流变性质的影响和制约机制。此外，采用高分辨显微学与谱学研究手段，探明了不同热处理及酸碱处理条件下，纳米矿物的微结构和表面基团性质变化，并进一步揭示了上述变化对其无溶剂纳米流体化的影响和机理。主要发现包括：对伊毛缟石和水铝英石的合成而言，合成体系中初始硅铝摩尔比是最重要的影响因素；伊毛缟石的形成生长过程可划分为五个阶段，首次观察到伊毛缟石形成初期球状原水铝英石向管状伊毛缟石的转化；当无溶剂纳米矿物流体中有机双分子层以静电引力作用，或具有较长有机柔性链，或无机“核”尺寸较大时，纳米流体具有更高的流变性；水铝英石和伊毛缟石在热/酸/碱处理下发生复杂而独特的物相结构、微观形貌、孔性和表面基团性质等变化，上述变化以及二者颗粒分散性对纳米流体的产率具有重要影响，但对流体的流变性质影响不大；埃洛石酸处理或热处理后，产物表面活性位点的增加能够提高其纳米流体的流动性。以上结果不仅提供了纳米矿物埃洛石、伊毛缟石和水铝英石无溶剂纳米流体化反应和纳米流体成分、微观结构和性质的第一手资料和数据，而且深化了对纳米矿物与有机质间界面作用机制的认知，对矿物表界面学和纳米矿物学均具有重要意义。