亚稳态分子间复合物（MIC）反应特性和微观点火机理的研究

Ignition is the initial reaction step of metastable intermolecular composites (MICs), among which the microscopic ignition mechanism is crucial to understand the reaction and propagation processes and is helpful to enhance the MIC synthesis efficiency. However, because of the experimental difficulties in directly monitoring the fast and highly exothermic reaction processes at the atomic scale, the ignition mechanism has been suffered from considerable debates for a long time. The microphysical origins of the influence of the component and loading condition on the reaction characteristics still remains unclear. In this project, we will carry out systemic studies on the ignition mechanism and reaction characteristics of Al/CuO and Al/MoO3 at the atomic and electronic scales based on molecular dynamics simulations and first-principles calculations. That is to say, we will investigate the dynamics and structure evolution of the core (Al)–shell (Al2O3) nanoparticle during ignition, the transport process of Al and O ion in Al2O3 shell, and the microscopic dynamics of the redox reactions at the Al-CuO and Al-MoO3 interfaces. Meanwhile, experiments will be conducted to verify the simulation results. This work would construct the bridge correlating the microscopic atom behaviors with the macroscopic reaction characteristics of MICs, and provide theoretical support for further interpretation, predication and exploitation of new MIC materials.

点火过程作为MIC反应的起始阶段，其微观机理对于揭示MIC的反应动力学和传播过程，改进MIC制备工艺都有着极为重要的意义。然而，由于实验技术在时空分辨率上的限制，MIC的微观点火机理还存在着大量争议，对影响MIC反应特性因素的微观物理本质尚缺乏深入的认识。本项目拟选择Al/CuO及Al/MoO3为研究对象，结合第一性原理和分子动力学模拟方法，在原子和电子尺度上对MIC的微观点火机理开展研究，探索组分特征和加载条件对MIC反应特性的影响规律及其微观物理本质,具体包括：核(Al)-壳(Al2O3)结构纳米粒子在点火过程中的结构演化和热/动力学行为；Al和O在Al2O3壳层中的输运行为；Al/CuO和Al/MoO3界面上的氧化还原反应的微观动力学过程；并结合实验对模拟结果进行验证。本研究将建立联系MIC微观尺度原子行为和宏观反应特性之间桥梁，为解释和预测MIC性能、开发新型MIC材料提供理论支撑

点火过程作为MIC反应的起始阶段，其微观机理对于揭示MIC的反应动力学和传播过程，改进MIC制备工艺都有着极为重要的意义。然而，由于实验技术在时空分辨率上的限制，MIC的微观点火机理还存在着大量争议，对影响MIC反应特性因素的微观物理本质尚缺乏深入的认识。本项目选择Al/CuO 及Al/MoO3 为对象，采用基于密度泛函理论的第一性原理方法和基于反应力场（ReaxFF）的分子动力学模拟方法对其点火机理和微观反应动力学过程进行研究，获得了不同加载条件下点火过程中核（Al）—壳（Al2O3）结构纳米粒子的结构演化和热力学行为特征；讨论了Al和O原子/离子在Al2O3壳层中的微观输运及其对壳层热力学性质的影响；研究了Al/CuO、Al/Fe2O3和Al/MoO3界面上氧化还原反应的微观动力学过程；探索了研究金属纳米Al为研究金属Al纳米颗粒在点火反应复杂环境下的碰撞和团聚烧结过程的微观结构演化、动力学响应及其背后的物理本质，构建了MIC的微观点火机理，并初步探索了组分特征和加载条件对MIC反应特性的影响规律及其微观物理本质。本项目研究获得的结果可以建立联系MIC微观尺度原子行为和宏观反应特性之间桥梁，为解释和预测MIC性能、开发新型MIC材料提供理论支撑。