热致调控高岭石的微观结构特性及其插层作用机理

Kaolinte is a kind of layered silicate mineral with nanosheet layered structure. Kaolinite organic intercalation compounds have vast application prospects in many new areas and have attracted growing interest. However, the intercalation of kaolinite is very hard because of the strong hydrogen bonds between the adjacent layers.With the enlightenment of the rehydration of metakaolinite to kaolinite, a new technique is proposed which contains the break of the hydrogen bonds between the adjacent layers by heating treatment and subsequently intercalation by organic molecular.The changes of microstructure and interlayer properties of different crystallization kaolinite before and after heating treatment will be studied. Subsequently, the intercalation of the heating treatment kaolinite will be studied. The influencing factors such as intercalate agents, react temperature and time are analyzed and evaluated.The theory of kaolinite heating treatment and intercalation are discussed based on the study of the structure and chemical property changes among the kaolinite, heating and intercalated kaolinite. The theory model is studied and established by molecular simulation assistance. The application of this intercalated heating kaolinite in the geopolymer is studied.This research not only promotes a novel technique for the intercalation of kaolinite but also provide method and theory for the functionalization of metakaolinite.

高岭石是一种具有纳米级层片状结构的硅酸盐矿物，经插层有机化修饰后，具有广阔的应用前景，但其层间具有较强的氢键作用，直接进行插层改性较为困难。基于热变高岭石经水化作用，可层间重建的特性,本课题拟采用热处理预先破坏高岭石层间的氢键作用，然后进行有机分子插层改性，制备功能性纳米高岭石插层复合物。主要研究内容如下：研究热处理对高岭石的微观结构、层间结合及化学活性的影响，探明热处理高岭石的微观结构特性。研究热处理程度、药剂种类和插层反应温度等因素对高岭石插层效果的影响。研究插层复合物的结构形态和化学特性，插层剂分子与热处理高岭石层间内表面的相互作用，结合分子模拟和动力学分析，探明其插层作用机理，建立理论模型。最后，初步研究热处理高岭石插层复合物在地质聚合物中的应用特性。本项目的研究，不仅为高岭石的插层改性提供了新的思路，也为热变高岭石的功能化提供了方法和理论依据。

选取了广西北海、河北张家口和淮北等三个地区的高岭土作为主要研究样品，对其进行了元素分析、矿物成分分析，采用XRD、SEM、TG、FTIR等手段对其热处理特性、微观结构和表面特性进行了研究分析。 .采用极性小分子、有机胺等药剂对热处理高岭石进行插层实验研究，对其插层特性和行为进行表征分析。醋酸钾能够直接插入热处理高岭石层间，但插层率较低。考察了温度、时间等对热处理高岭石水化的影响，研究了热处理高岭石的水化特性和规律，对热处理高岭石的水化作用机理进行分析。水热的高温作用下与煅烧活化的硅和铝原子发生反应，形成硅羟基、铝羟基和铝氧羟基，逐渐形成硅氧键、硅氧铝键。在此水化过程中，逐渐恢复的高岭石晶胞单元彼此解离，并在原位进行晶体生长，由于水的界面张力作用而形成球形高岭石颗粒。.实验研究了氯化锂、氯化钠、氯化锌等无机盐，乙醇，八胺、十二胺，尿素、二甲基亚砜、醋酸钾等药剂对热处理高岭石的水化调控和插层作用。分析研究了热处理高岭石的水化调控和插层作用行为，探明了热处理高岭石水化过程中的形貌调控机制和有机分子插层机理。二甲基亚砜在热处理高岭石水化过程中进入高岭石层间，层间距扩大到1.26nm。本研究通过高岭石的煅烧活化-水热处理-药剂调控的技术路线成功制备了球状、棒状和片状纳米高岭石，为类似矿物材料的制备提供了新的技术手段和理论支撑，同时为自然界高岭石形态多样的成因提供了新的探索方法。. 最后对水化调控插层改性高岭石的应用特性进行初步了研究，重点探究了其对水体污染物亚甲基蓝的吸附特性，研究了吸附影响因素，建立了其吸附模型。