高岭石的结构有序度和形貌特性对其“片-管”转化过程的影响及制约机制研究

Tubular halloysite is a naturally occurring porous material suitable for use as filler in polymers, nanoreactor/nanotemplate for the synthesis of functional materials, adsorbent for pollution remediation, and carrier for the loading and controlled release of guest molecules. However, halloysite has a low deposit, and exhibits significant diversity in morphology between and even within deposits. These drawbacks could severely limit the applications of halloysite in the abovementioned fields. This problem could be effectively resolved by delamination and curling of platy kaolinite (with high deposit and high purity) to form tubular halloysite with high tubule quality. Since the tubular halloysite was transformed from kaolinite, the structural order and the morphology of the parent kaolinite may have influence on the transformation efficiency and the morphology of tubular halloysite, respectively. The present proposal starts with detail discussion on the structural order of kaolinite collected from different deposit, and investigates the constraint of structural order of kaolinite on its transformation to tubular halloysite. Moreover, the relationship between the morphology of parent kaolinite and the morphological parameter of tubular halloysite is also studied. The results will be in favor of the further understanding of the microstructure and micromorphology of kaolinite, and provide the key theory and experimental basis for orientated regulating the morphology of tubular halloysite. Consequently, there exists of considerable research meanings.

管状埃洛石在聚合物纳米复合材料、纳米反应器/纳米模板、环境修复、活性分子负载及缓释控释等领域具有多种应用价值，但是天然埃洛石的相对稀缺性和低形貌结构均匀性严重限制了其在工业上的应用。片状高岭石经插层剥离处理后可发生“片-管”转化，并形成管状埃洛石，这是制备高纯和高均匀性管状埃洛石的一种有效的途径。然而，从矿物学角度而言，高岭石的矿物特性（结构有序度、形貌等）可能对其“片-管”转化产生根本上的制约作用。本项目拟系统研究高岭石的结构有序度，并探讨其对“片-管”转化的制约作用；此外，还将探讨高岭石的形貌对管状埃洛石形貌的制约作用。所获成果将显著提升对高岭石矿物微结构和微形貌的认识，为实现定向调控管状埃洛石的形貌结构提供理论和实验依据，因此具有重要的研究意义。

片状高岭石和管状埃洛石具有相似的晶体结构和化学组成。高岭石经插层剥离处理后可发生“片-管”转化形成类埃洛石纳米管，可作为铝硅酸盐纳米管在聚合物纳米复合材料、纳米反应器/纳米模板、环境修复、活性分子负载及缓释控释等领域具有多种应用价值。本项目系统研究了高岭石结构有序度和微形貌对其片管转化的影响和机理；高岭石和埃洛石作为药物载体的负载释放性能；埃洛石表面性质对高分子复合材料结晶行为的影响以及对微藻捕收的影响。主要结论有：①八面体C位空隙含量是快速、有效评价高岭石结构有序度的方法；②高岭石晶体结构有序度和颗粒尺寸共同制约客体分子在高岭石层间域的插层行为，高岭石颗粒的发育程度直接决定最终形成的纳米管质量；③甲氧基改性高岭石的层间域是5FU的负载位点，能够实现5FU的选择性负载和控制释放；④埃洛石微结构和微形貌直接制约埃洛石作为载体的负载活性；⑤埃洛石的表面性质可实现定向调控，并直接影响PBAT的结晶行为；⑥硅烷接枝改性埃洛石能够有效提升微藻捕收效率，且不影响微藻的油脂提取。项目所获成果显著提升了对高岭石和埃洛石的微结构和微形貌的认识；提供了快速和准确甄别高岭石和埃洛石原料实际应用领域的判断依据和实验方法；探索了一种5FU缓释药物的口服给药方式，开发了一种简单的、环境友好的、能够工业化实现的调控高分子复合材料结晶行为的方法，发明了一种能源微藻的高效捕收剂；提升了高岭石和埃洛石石在医药行业、微藻捕收、水体藻类污染控制等高值化利用的应用途径。本项目具有重要的研究和应用价值。