Titi H M, Marrett J M, Dayaker G, Arhangelskis M, Mottillo C, Morris A J, Rachiero G P, Friščić T, Rogers R D
Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada.
School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Sci Adv. 2019 Apr 5;5(4):eaav9044. doi: 10.1126/sciadv.aav9044. eCollection 2019 Apr.
Hypergolic materials, capable of spontaneous ignition upon contact with an external oxidizer, are of critical importance as fuels and propellants in aerospace applications (e.g., rockets and spacecraft). Currently used hypergolic fuels are highly energetic, toxic, and carcinogenic hydrazine derivatives, inspiring the search for cleaner and safer hypergols. Here, we demonstrate the first strategy to design hypergolic behavior within a metal-organic framework (MOF) platform, by using simple "trigger" functionalities to unlock the latent and generally not recognized energetic properties of zeolitic imidazolate frameworks, a popular class of MOFs. The herein presented six hypergolic MOFs, based on zinc, cobalt, and cadmium, illustrate a uniquely modular platform to develop hypergols free of highly energetic or carcinogenic components, in which varying the metal and linker components enables the modulation of ignition and combustion properties, resulting in excellent hypergolic response evident by ultrashort ignition delays as low as 2 ms.
自燃材料在与外部氧化剂接触时能够自燃，作为航空航天应用（如火箭和航天器）中的燃料和推进剂至关重要。目前使用的自燃燃料是高能、有毒且致癌的肼衍生物，这促使人们寻找更清洁、更安全的自燃推进剂。在此，我们展示了第一种在金属有机框架（MOF）平台内设计自燃行为的策略，即利用简单的“触发”功能来释放沸石咪唑酯框架（一类常见的MOF）潜在的、通常未被认识到的能量特性。本文介绍的六种基于锌、钴和镉的自燃MOF，展示了一个独特的模块化平台，用于开发不含高能或致癌成分的自燃推进剂，其中改变金属和连接体成分能够调节点火和燃烧特性，从而产生优异的自燃响应，超短点火延迟低至2毫秒就是明显例证。
