【摘要】 针对当前六硝基六氮杂异伍兹烷(CL-20)微球制备中粒径较大且均匀性差的问题，提出了一种能够控制液滴生成模式的声流控技术。该技术将液滴微流控技术与声表面波技术相结合，提高了含能乙酸乙酯液滴的尺寸均匀性，利用溶剂-非溶剂重结晶法制备了微米级CL-20/NC含能微球。采用高速相机对液滴生成过程进行监测，结果显示，声表面波技术能有效控制液滴生成模式的转变，避免液滴生成过程中因材料析出和通道堵塞等原因引起的液滴生成模式的不可控转变，实现了液滴均匀连续的生成。使用场发射扫描电镜对具有不同CL-20含量、不同NC含量和不同粒径的微球形貌进行了表征，结果显示，通过降低CL-20含量、增加NC含量或增大微球粒径等方式，可以降低微球的表面粗糙度，减少表面缺陷，同时在声表面波技术辅助下，微球粒径变异系数从39.33%降至7.51%,极大地提高了微球的均匀性。通过X射线衍射仪和热质量分析仪对具有不同粒径的CL-20/NC微球的晶体结构和热力学性能进行了表征，结果显示，中位粒径为20μm的微球(分解峰温为229.04℃)的热稳定性优于中位粒径为7μm的微球(分解峰温为228.22℃)的热稳定性，而中位粒径为7μm的微球的反应剧烈程度与能量密度较大，其损失质量率(84.3%)和放热量(12.05 mW/mg)均高于中位粒径为20μm的微球的损失质量率(80.2%)和放热量(8.84 mW/mg)。声流控技术成功制备了粒径更小且均匀性显著提高的CL-20/NC含能微球，为高能量密度材料的优化设计与应用提供了重要参考。更多还原

【Abstract】 To enhance the performance and safety of energetic materials(CL-20), microfluidic technology has been widely used in the microsphere preparation process. By integrating droplet microfluidics with surface acoustic wave technology, ethyl acetate droplets with exceptional uniformity in size are created. Subsequently, micrometer-sized CL-20/NC energetic microspheres are fabricated using a solvent-nonsolvent recrystallization approach. The droplet generation process is monitored employing a high-speed camera. The results demonstrate that surface acoustic wave technology can effectively regulate the transition of droplet generation modes, averting uncontrollable shifts caused by material precipitation and channel obstructions, thereby ensuring consistent and uninterrupted droplet generation. The morphologies of microspheres with varying particle size, CL-20 contents and NC contents are characterized by field emission scanning electron microscopy(SEM). The findings suggest that diminishing CL-20 content, augmenting NC content, or increasing microsphere size can diminish surface roughness and minimize defects. With the support of surface acoustic wave technology, the coefficient of variation in microsphere size decreases significantly from 39.33% to 7.51%, notably enhancing uniformity. The crystal structure and thermodynamic traits of CL-20/NC microspheres of different sizes are characterized using X-ray diffractometry and thermal analysis. The results indicate that microspheres with a median particle size of 20 μm display superior thermal stability, with a decomposition peak temperature of 229.04 ℃, surpassing that of microspheres with a median particle size of 7 μm at 228.22 ℃. Microspheres with a median size of 7 μm exhibit heightened reactivity and energy density, manifesting a higher mass loss rate(84.3%) and heat release(12.05 mW/mg) compared to their 20 μm counterparts, which demonstrate a mass loss rate of 80.2% and heat release of 8.84 mW/mg.更多还原