Room-Temperature Aqueous Synthesis of Copper Nanoparticles and Their In Situ Conversion to Copper Azides

Area of Science:

• Materials Science
• Energetic Materials Chemistry
• Nanotechnology

Background:

• Copper azides are attractive energetic materials for miniaturized pyrotechnics due to their rapid detonation and high initiation energy.
• Controllable synthesis of copper nanoparticle precursors and their conversion to copper azides under mild conditions are significant challenges.

Purpose of the Study:

• To develop a controllable method for preparing copper azide micro-charges.
• To characterize the morphology, detonation velocity, and initiation performance of the synthesized copper azides.

Main Methods:

• Synthesized copper nanoparticles via a coordination-assisted aqueous reduction method at room temperature using nitrilotriacetic acid disodium salt.
• Prepared copper azide micro-charges through in situ gas-solid reaction with hydrazoic acid (HN3) gas.
• Characterized morphology using SEM, detonation velocity using electrical probe, and initiation performance via flyer impact tests.

Main Results:

• Copper nanoparticle precursors were successfully synthesized under mild, air conditions.
• Morphological evolution of copper azides followed a three-stage pattern: nucleation, growth, and layer formation.
• Detonation velocity averaged (5.10 ± 0.07) × 10³ m/s, and successful initiation of HNS-IV explosive was achieved with a 1.00 mm thick charge.

Conclusions:

• A novel and mild preparation methodology for copper azide micro-charges was established.
• The synthesized copper azides exhibit excellent detonation and initiation properties.
• This work provides a foundation for applying copper azides in micro-initiation systems.