基于含氟材料的纳米铝粉包覆方法及助燃机理研究

Fluorine-containing polymer materials have antioxidant properties. Recent research has found that fluorine-containing polymer materials could also greatly improve the combustion efficiency and heat release of Aluminum powder. This project intends to take full advantage of those properties, so that problems related to the low content of active aluminum in nano Al powder and the low completion rate of the reaction in energetic composite for micron grade aluminum could be solved. Meanwhile, the energy density of energetic composite could be improved, as well as the energy release efficiency. The combustion-supporting mechanism of fluorine-containing polymer materials will also presented. In this project, experiment and numerical simulation will be combined together to study the methods to coat nano aluminum powder with fluorine-containing polymer materials by employing electrostatic spray technology, which has advantage in disperse and purity of the product, resulting in increasing the content of active Aluminum in nano Al powder. In the meantime, the molecular structure of Al/F system will be established and molecular dynamics(MD) simulation will be employed to reveal the forming mechanism of its core-shell structure, then some analysis means, like X-Ray Diffraction, Infrared Spectrum, X-ray photoelectron spectroscopy, will be employed to verify the results. The reaction process of Al/F system will be calculated by MD methods to find out the reaction routine of Al/F system and the combustion-supporting mechanism of fluorine-containing polymer materials. Finally, the experiments related to the combustion properties and the practical exploration of Al/F system in thermobaric explosives will be conducted, which will verify the feasibility to apply the Al/F system in energetic composite.

含氟高分子材料具有抗氧化特性。近年来研究发现，含氟材料还能极大地提高铝粉的燃烧效率，提高放热量。本项目拟利用含氟材料以上双重特性，解决纳米铝粉中活性铝含量低和微米铝粉在复合含能材料中反应不完全的问题，提高其能量密度和能量释放效率，揭示含氟材料的助燃机理。本项目拟采用试验与数值模拟相结合的手段，利用静电喷雾技术特有的微球分散性好、产物纯度高等优点，研究含氟材料包覆纳米铝粉的方法，提高纳米铝粉中活性铝含量；同时建立纳米铝粉-含氟材料体系的分子模型，利用量子化学计算方法对Al/F体系进行分子构型模拟，揭示Al/F体系核壳结构的形成机理，并用XRD、红外光谱、X射线光电子能谱等试验手段进行验证；开展Al/F体系反应过程的分子动力学计算，获得Al/F体系反应历程，揭示含氟材料对铝粉的助燃机理；进行Al/F体系燃烧特性研究和在温压炸药中的应用研究，探索Al/F体系在复合含能材料中应用的可行性。

含氟高分子材料具有良好的抗氧化特性，同时，含氟材料还能极大地提高铝粉的燃烧效率，提高放热量。本项目利用含氟材料的以上双重特性，解决纳米铝粉中活性铝含量低和微米级铝粉在复合含能材料中反应不完全的问题，提高复合含能材料的能量密度和能量释放效率，揭示含氟材料的助燃机理。本项目紧密结合含氟材料的宏观性能和复合粒子的微观结构，利用试验和分子动力学（MD）模拟相结合的方法开展研究，为复合粒子设计和应用提供理论支撑。主要研究工作及成果如下：.设计了正交试验，系统地研究了喷雾过程中针头内径、推进速度、接收距离、输出电压等对制备效果的影响，得到了形貌最佳、放热性能良好的n-Al/PVDF复合粒子制备条件。.开展了PVDF与纳米铝粉的界面相互作用研究，并研究了表面活性剂在样品制备过程中的作用。通过试验与模拟的手段研究了不同类型的表面活性剂的作用机理，解释了表面活性剂对纳米铝粉悬浮液的分散作用；另外研究了典型含氟材料PVDF包覆n-Al粉的复合体系在不同温度下的结合能变化情况，为实验研究提供理论指导。.利用试验与分子动力学模拟相结合的方法，获得了复合粒子结构与PIR的关系，明确了PIR与n-Al/PVDF界面反应的联系，从界面结构与界面反应的角度解释了复合粒子的助燃机理，另外从复合粒子反应动力学的角度解释了进一步阐述了PVDF对n-Al的助燃机理。.为验证n-Al/PVDF复合粒子在炸药中应用效果，制备了含有n-Al/PVDF复合粒子的炸药样品，开展了内爆条件、敞开条件下爆炸试验，结果表明含有n-Al/PVDF复合粒子的炸药样品具有更高的冲击波爆炸参数。