Silver/polydopamine/HMX nanocomposite: novel functionalized catalyzed energetic matrix with superior decomposition kinetics

Abstract

Surface engineering of energetic materials can secure novel decomposition characteristics. Nature can inspire novel solutions. Polydopamine, with strong adhesion power of mussel proteins, can open new venues for the facile development of functionalized energetic materials. HMX, one of the most powerful energetic materials in use, was surface modified with PDA. The reactive amine groups of PDA surfactant were employed for noble metal catalyst deposition. Silver nanocatalyst was deposited on HMX surface. Uniform deposition of silver nanocatalyst was assessed using EDAX detector. Decomposition kinetics was investigated via isoconversional (model free) and model fitting. Kissinger, Kissinger–Akahira–Sunose (KAS), integral isoconversional method of Ozawa, Flynn, and Wall (FWO), and differential isoconversional method of Friedman. Silver nanocatalyst offered an increase in HMX decomposition enthalpy by 32.4%. In the meantime, HMX activation energy was decreased from 350 ± 2.53 to 284.9 ± 1.5 kJ mol−1 by Friedman method. Silver nanocatalyst could combust exothermically; it could induce condensed phase reactions that could boost HMX decomposition. Silver nanocatalyst experienced change in HMX decomposition model from diffusion reaction (D1) to (A3) known as three-dimensional random nucleation and growth. Surface modification with PDA secured enhanced HMX sensitivity to falling mass impact by 40%.