膨润土结构/功能调控制备环保型沥青改性剂及其机理研究

Preparation of advanced materials based on the characteristics of natural minerals is becoming a frontier field of interdisciplinarity. This project aims to construct multifunctional composite materials by organic intercalation and loading of CuO-CeO2 nanoparticles, on the basic of making full use of the layered structure features of natural bentonite. The road and catalytic performances of this new asphalt modifier can be comprehensively controlled through composition adjustment and parameter optimizing. This project will analyze the structure evolution of bentonite and the mechanism of nanoparticles constructing, ascertain the impact of interfacial characteristics and size effect of CuO-CeO2 nanoparticles for the properties, and finally find the relation between the microstructures and the enhanced properties of the composites. Furthermore, first-principles density functional theory calculations is employed to build atomic structure model for the complex system in this project, revealing the combination mechanism of the interface coupling among functional nanoparticles, bentonite, and asphalt at the atomic and molecular levels. The accomplishment of the project could show important theoretical significance and application value for the high-valued utilization of mineral resources, and offer new ideas for the chiastopic fusion of minerals, material, environment, and roads disciplines.

基于天然矿物特性构筑新材料是多学科交叉的前沿领域。本项目充分利用膨润土的层状结构特性，采用有机插层结合CuO-CeO2纳米颗粒负载进行结构调变与功能组装构筑多功能复合材料，通过工艺优化与组分调控，实现新型沥青改性剂路用与催化性能的综合调控。研究制备过程中膨润土的结构演变及组装纳米颗粒的构筑机理，查明复合体系的界面特性和尺寸效应对材料性能的影响规律，解析复合材料微结构与性能强化之间的关系。利用第一性原理的密度泛函计算，建立复合体系结构模型，从原子、分子层次揭示功能颗粒、矿物基体以及沥青的界面耦合机制。本项目的完成对矿物资源的高值化加工与应用具有重要的理论意义和应用价值，也为矿物、材料、环境、道路等学科交叉融合提供崭新的思路。

矿物复合材料在道路领域的高值化利用及路域综合环境提升具有较高的环境效益和社会效益。本研究基于天然膨润土的化学成分及片层状形貌结构特点，确定了适宜有机插层剂对天然膨润土进行结构调变的工艺及方法；通过深入分析天然膨润土有机化对基质沥青的微观结构、常规物理性能、流变性和老化特性的影响，发现膨润土有机化可提高膨润土在沥青中的分散性、高温稳定性；分析发现调变后的膨润土层状结构增加了对基质沥青的吸附作用，从而提高了沥青的抗老化性；制备了多种功能颗粒复合膨润土，并分析其对基质沥青的高低温流变性、抗老化性和催化净化功能，阐明了功能负载膨润土对沥青的改性机理以及对尾气的催化降解机理；采用分子动力学模拟，建立体系结构模型，明确复合材料组成、结构对性能的作用机制。研究开发的绿色环保型改性沥青，不仅可以提高沥青性能还可以有效净化路域近地表环境，实现交通行业绿色、安全、高效发展。