水热-热压耦合过程原位可控制备粘土基陶瓷/碳及其性能研究

Clay-based ceramic is characterized by low toughness, poor strength and functional deficiency. It is necessary to improve the mechanical and functional properties of clay-based ceramic. This project aims to prepare ceramic/carbon composite through in situ hot pressing of clay/carbon nanocomposite which is prepared by hydrothermal treatment of clay and saccharides. Based on the excellent adsorption ability, sintering and template roles of clays, the carbon source (saccharides) will carbonize as nanocarbons on the surface of clay. Also, the resultant carbon will uniformly distribute in the ceramic matrix and contribute a conductivity to composite. The ceramic/carbon can be obtained by the following two steps. Firstly, the starting materials will be hydrothermally treated at low temperature to obtain clay/carbon nanocomposite. Then the clay/carbon will be further hot pressed to get ceramic/carbon. The effect of operational conditions on the crystal structures, chemical components, electrical conductivity, surface and mechanical properties will be emphasized. A series of mechanisms will be detailedly proposed, such as the growth of carbon, formation of ceramic and carbon and toughness increased from carbon. Finally, some theories and methods about in situ preparation of creamic/carbon through hydrothermal-hot pressed process are built, which is useful for the research field of ceramic. The results are meaningful for the development of some researh fields, such as carbon materials, ceramic materials, nanotechnology, etc..

粘土基陶瓷具有韧性低、强度欠佳、功能性不足等缺点。本项目利用粘土矿物的低温模板以及高温烧结特性，以糖类天然高分子为碳源，通过水热-热压耦合过程将碳原位均匀分布于陶瓷基体中，实现陶瓷结构-功能一体化设计，创制一种新型陶瓷/碳复合材料。通过低温水热过程，在矿物表面可控负载纳米碳，获得陶瓷前驱体即粘土/碳；然后热压获得陶瓷/碳。重点研究材料制备方法及反应条件对材料组成、微观结构、表面性质、力学性能和导电性能的影响；比较不同碳源和矿物模板的水热-热压碳化过程，揭示矿物和碳在热压过程中的结构变化和协同影响机制，控制碳在陶瓷基体中的赋存状态和结构特征；揭示不同微观几何结构碳对陶瓷增韧增强及导电机理；最终形成结构-功能一体化陶瓷/碳复合材料的水热-热压耦合过程原位可控制备的理论与方法体系，为粘土基陶瓷的增韧增强和功能化奠定理论与方法基础。成果对陶瓷材料科学、碳材料科学和纳米科学等学科研究均具有重要意义。

粘土基陶瓷具有韧性低、强度欠佳、功能性不足等缺点。项目利用粘土矿物的低温模板以及高温烧结特性，以糖类天然高分子为碳源，通过水热-热压耦合过程将碳原位均匀分布于陶瓷基体中，实现陶瓷/碳的原位可控制备，创制一种新型结构-功能一体化即力学性能好并兼具导电功能的陶瓷/碳复合材料。通过低温水热过程，在矿物表面可控负载纳米碳，获得陶瓷前驱体即粘土/碳；然后热压获得陶瓷/碳。重点研究材料制备方法及水热-热压条件对材料组成、微观结构、表面性质、力学性能和导电性能的影响；研究矿物和添加剂种类对水热-热压碳化过程的影响，揭示矿物和碳在热压过程中的结构变化和协同影响机制，控制碳在陶瓷基体中的赋存状态和结构特征；揭示碳对陶瓷增韧增强及导电机理；为粘土基陶瓷的增韧增强和功能化提供了一种新方法新理论。研究成果对陶瓷材料科学、碳材料科学和纳米科学等学科研究均具有重要意义。