Structure-Induced Energetic Coordination Compounds as Additives for Laser Initiation Primary Explosives.

Area of Science:

• Materials Science
• Energetic Materials
• Chemical Engineering

Background:

• Traditional electrical initiation of primary explosives is less reliable than laser ignition.
• Commercial lead azide (LA) requires high laser energy (2402 mJ) for detonation.
• Existing laser-ignitable materials have limited detonation capabilities and high energy requirements.

Purpose of the Study:

• To design novel laser-ignitable primary explosives using energetic coordination compounds (ECCs).
• To reduce the minimum laser initiation energy (Emin) for explosives.
• To develop additives for lead azide (LA) to enhance laser ignition sensitivity.

Main Methods:

• Synthesized two azide and tetrazole-based ECCs: [Co(N3)(2-bmttz)(H2O)]2 (1) and [Co(N3)(2-bmttz)(MeOH)]2 (2).
• Incorporated ECC 1 as an additive into lead azide (LA) to create material 1e (4 wt.%).
• Evaluated laser initiation threshold (Emin) and time (Tmin) for LA and material 1e.
• Tested the detonation capability of 1e on RDX using minimal laser energy.

Main Results:

• Material 1e demonstrated an ultra-low laser initiation threshold (Emin = 1.6 mJ) and ultrafast time (Tmin = 0.2 ms).
• The Emin of 1e was 1/1500th of that required for pure LA.
• 30 mg of 1e successfully detonated RDX using only 1.6 mJ of laser energy.
• ECC 1 showed superior performance over ECC 2 due to enhanced radical generation and photothermal conversion.

Conclusions:

• Azide and tetrazole-based ECCs, particularly compound 1, significantly enhance laser ignition sensitivity of primary explosives.
• This research offers a paradigm shift towards developing laser-driven micro-detonators with high performance and low energy consumption.
• The findings have potential applications in micro-initiation systems requiring precise and low-energy laser triggering.