嵌入包覆型AlH_(3)含能复合颗粒的制备及其反应特性

Preparation and Reactivity Properties of Embedded⁃Coated AlH3 Energetic Composite Particles

为了提高三氢化铝(AlH_(3))的稳定性,采用声共振与喷雾干燥技术相结合的方法制备了3种嵌入包覆型AlH_(3)@Al@xAP(AHAPs)含能复合颗粒,AlH3@Al和AP的质量比分别为9∶1(AHAPs‑10%)、7∶3(AHAPs‑30%)和1∶1(AHAPs‑50%)。采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线粉末衍射(XRD)等分析手段对AHAPs及其凝聚相燃烧产物的形貌和结构进行表征,利用热重‑差示扫描量热仪(TG‑DSC)、真空安定仪(VST)研究了样品的热反应活性和稳定性。结果表明,AHAPs含能复合颗粒不仅提高了AlH3的稳定性,同时还促进了AP的分解,随着表面AP包覆含量的增加,AlH3的起始分解温度提高了8.5~11℃,AP的高温分解峰温降低了约81.6℃。与AlH3的分解时间(1006 min)相比,AHAPs‑50%复合颗粒的分解时间提高了近50.9%,达1518 min。此外,嵌入包覆型复合颗粒AlH3@Al/63.5%AP的反应热(9125.6 J·g^(-1))与机械混合样品相比,提高了1054.1 J·g^(-1),且凝聚相燃烧产物粒径更小,说明其燃烧更加完全、燃烧效率更高。

To improve the stability of aluminum hydride(AlH3),three kinds of embedded‑coated AlH3@Al@xAP(AHAPs)energetic composite particles were prepared by the combination of using acoustic resonance and spray drying technology.The mass ratios of AlH3@Al and AP were 9∶1(AHAPs‑10%),7∶3(AHAPs‑30%),and 1∶1(AHAPs‑50%),respectively.The morphologies and structures of the AHAPs and their condensed combustion products were characterized by SEM,EDS,and XRD.The thermal reactivity and stability of the prepared samples were comparatively studied by TG‑DSC analysis and vacuum stability tester(VST).Results show that AHAPs energetic composite particles could not only improve the stability of AlH3 but also promote the decomposition of AP.With the increase of AP content,the initial decomposition temperatures of AlH3 are increased by 8.5-11℃,and the peak temperature at high‑temperature decomposition stage of AP is decreased by about 80℃.Compared with the total decomposition time of pure AlH3(1006 min),the decomposition time of AHAPs‑50%composite particles extend to 1518 min,which corresponds to a 50.9%increment.In addition,the reaction heat of embedded‑coated composite particles AlH3@Al/63.5%AP reaches 9125.6 J·g^(-1),which is 1054.1 J·g^(-1)higher than that of mechanically mixed samples,and the particle sizes of the condensed combustion products appear to be finer,indicating that their combustion become more complete and the combustion efficiency is greatly enhanced.