超疏水纳米Al/MOx含能器件的可控构建及放热稳定性探究

Energetic devices are widely used in military industry, machinery and electronics, aerospace and other fields due to their high energy density and violent detonation process. However, the complex structures in devices and highly active metal being easily oxidized lead to the poor long storage performance and exothermic stability, and the low-cost fabrication of energetic devices. There is little report on the design of superhydrophobic energetic devices, and the mechanism of improving their long-term heat release stability is still not clear. Thus, this project will take the MEMS devices as substrates, and construct the superhydrophobic Al/MOx energetic device via the combination of electrophoretic deposition method (EPD) for preparing nano-Al/MOx (M=Co, Mn, Ni) energetic films with network-like structures, the introduction of modified liquid with low surface energy, and the microwave-assisted heat treatment technology. The EPD kinetic model based on different energetic systems will be established, and the EPD film-forming mechanism and relevant surface modification mechanism will be clarified. The superhydrophobicity of the modified energetic devices will be analyzed through experiments of liquid impact, immersion of devices, self-cleaning and so on. Meanwhile, the heat output stability and hydrophobicity of Al/MOx energetic devices will be verified by the ultralong unprotected weatherability experiments under the simulated natural environments. Results of this study will be an improvement of the cognition of energetic materials and their devices, and provide new ideas for the construction of different types of energetic devices. In addition, they will provide strong scientific basis and lay a solid theoretical foundation for the controllable design, the realization of long-term storage and transportation, and stable heat output of various energetic devices.

含能器件因其高能量密度和剧烈的爆燃过程在军工、机电、航空等领域中应用广泛。然而，基底结构复杂以及金属的活性高、易被氧化，导致含能器件低成本制备难、长储性差且放热性能稳定性差。目前关于超疏水含能器件的设计探究甚少以及放热稳定性提升的机理尚不清楚。因此，本项目以MEMS器件为基底，通过电泳法设计具有类网状结构的Al/MOx（M=Co, Mn, Ni）含能薄膜并引入低表面能的改性液，结合微波辅助热技术，构建超疏水纳米Al/MOx含能器件；建立不同体系的电泳成膜动力学模型，阐明相关的电泳成膜和表面改性机理；通过液滴冲击、浸泡、自清洁等实验，分析含能器件的超疏水性能；同时模拟自然环境下长期耐候性实验，验证Al/MOx含能器件的疏水及放热稳定性。研究结果可完善含能材料及其器件化的认知，为不同类型含能器件的构建提供新思路，也为实现含能器件的长期储运且稳定的热量输出提供有力的科学依据和奠定坚实的理论基础。

本项目基于具有广泛应用的微型铝热含能器件成膜困难，以及铝基含能器件因其亲水性和金属（Al等）易氧化等缺点导致放热性能易衰减或稳定性差的困境，系统地完成了以MEMS微型点火桥为基底的超疏水型类网状Al/MOx（M=Co, Mn, Ni）含能薄膜器件的构建。本项目提出的制备技术为筛选悬浮液，优化电泳沉积工艺并结合表面改性技术，具有成本低廉，操作便捷，效率高和普适性出众等优点。制备的三种超疏水含能体系的表面均表现出良好的分布均匀性且具有较为明显类网状的多孔微纳二元结构，以及较高的结晶度和纯度，为设计超疏水表面和热能的快速释放均提供了良好的结构基础。完成了电泳成膜动力学数据模型的建立，即电泳组装效率能通过不同的电泳时间进行较为精确的控制，进而优化产物的燃料（Al粉）和氧化物的反应摩尔比。此外，含能体系的疏水化主要通过氟化物在醇液中的水解和脱水过程，以及热处理固化来实现。特别的，三种超疏水含能器件的水接触角均高达168°以上，通过水浸泡试验和污染实验表现出几乎完美的斥水性和自清洁能力，以及在高湿度环境（相对湿度RH>95%）下依然表现出出色的抗候性。尤其是，通过暴露长达一年的实验，所有器件样品的微观结构和疏水性几乎没有变化。此外，暴露实验前后的样品的活化能（Ea），放热性能（Q）和爆燃性能均表现出出色的稳定性。总之，本项目提出的低成本且高效的超疏水Al/MOx（M=Co, Mn, Ni）含能器件的设计方案，能为广泛应用于国防、军工、电子等领域的其他功能型稳定型含能器件的构建提供有价值的技术参考和理论支撑。