Core‐Shell Hetero‐Framework derived Copper Azide Composites as Excellent Laser‐Ignitable Primary Explosives

Abstract

Laser initiation has attracted increasing interest owing to its extraordinary safety and high reliability. However, traditional metal complex‐based laser‐ignitable primary explosives are limited by high input laser energy and low detonation ability. In this study, an efficient laser‐ignitable primary explosive‐based copper azide is prepared by constructing core‐shell hetero‐framework Cu‐MOF@COF as the precursor. The pyrolysis of Cu‐MOF@COF hybrid material affords copper azide (CA) nanoparticle confined in a porous carbon shell, referred to CA@C Shell. The evenly coated porous carbon shell functions as light‐to‐heat conversion layer efficiently promoting the laser initiation process of inside CA. Consequently, CA@C Shell can be initiated at lower laser energy thresholds (0.80 mJ at 1064 nm). This value is significantly lower than typical laser ignitable metal complex tetraamine‐cis‐bis(5‐nitro‐2H‐tetrazolato‐N2)cobalt(III)perchlorate (726 mJ at 808 nm). Moreover, the CA@C Shell successfully detonates the secondary explosives CL‐20 by laser energy when it is assembled in a micro‐detonator system. This study offers a unique method for constructing high performance laser‐ignitable primary explosives for micro‐detonator applications.

Efficient Synthesis of Nanoscale Cadmium Azide from Intercalated Cadmium Hydroxide for Nanoexplosive Applications

“…Traditional primary explosives represented by lead azide (LA) and lead styphnate (LS) fail to satisfy the requirements for the charge of microinitiating devices because of the limitation of their ordinary detonation ability, unsatisfactory sensitivity performance, and mismatched particle size with micro-electromechanical systems (MEMS). − Fortunately, nanosized primary explosives with large specific surface areas, multiple active sites, and fast energy release rates are expected to applicate in microinitiating devices. − Therefore, nanoscale copper azide (CA) is considered the most promising primary explosive for microinitiating devices due to its excellent detonation ability and environmental friendliness. However, CA’s ultrahigh electrostatic sensitivity and poor high-temperature resistance limit its practical application. ,− Although many researchers have prepared modified CA by doping conductive materials, the most effective modified composite material only can endure 9 mJ of electrostatic energy, indicating a high-security risk. ,,− Besides, both CA and its modified products will decompose rapidly around 200 °C and lose their detonation ability, detonating the secondary explosives unreliably, ,− while high-temperature environments generally exist in the military and civilian fields. − Therefore, it has become an urgent demand to develop a nanoscale primary explosive with excellent detonation, appropriate sensitivity, and outstanding high-temperature resistance to adapt to the development of microinitiating devices.…”

A three-dimensional energetic coordination compound (BLG-1) with excellent initiating ability for lead-free primary explosives

“…The threshold of the laser-initiation of BLG-1 was only 13 mJ at 808 nm, which is significantly lower than that of the conventional laser-ignitable primary explosive BNCP (726 mJ at 808 nm). 38 These findings demonstrated the potential of BLG-1 as a laser-ignitable primary explosive.…”

Composite materials based on covalent organic frameworks for multiple advanced applications

“…Both MOFs and COFs are representative crystalline porous materials. [165][166][167] COFs-MOFs composites can combine the advantages of MOFs and COFs. Up to now, the synthesis strategies of composite materials based on MOFs and COFs mainly involve imine formation, [168] boron-oxygen formation, [169] direct condensation, [170] post-synthetic modification, [171] π-π stacking interaction, [172] MOF-in-COF assembly strategy and modular total synthesis.…”