Energy release prediction and structure characterization of nano aluminum powder in situ coated by polyethylene glycol

Abstract

In order to solve decreasing of reactivity of nano aluminum powder due to the alumina shell on the surface, used polyethylene glycol (PEG) as a coating material to obtain in situ PEG on nano aluminum particles with electrical explosion wires method. Based on the minimum free energy principle and BKW equation, the combustion and explosion performance of the coated sample is estimated. SEM and TEM to observe sample’s morphology and then used dynamic light scattering (DLS) nano-particle size analyzer to characterize sample’s particle size distribution. The chemical states of surface elements were analyzed by X-ray photoelectron spectroscopy. The thermal behavior of three samples were characterized by simultaneous thermal analyzer. The combustion heat, pressure-time curve, active Al content and vacuum stability was measured according to national standards. The results show that the coated sample was nearly sphere and particles were deduced multi-core structure. The active Al content reached 71.17% which is 12.53% higher than raw nano-Al particles. It was proved that PEG relieves oxidation of nano-Al, and the coating is stable. The coated samples can release energy more rapidly compared to micro-Al. The PVA in situ coated nano-Al particles has high active Al content and reactivity. Its application in energetic materials has good prospects.