Improve the interfacial adhesion, corrosion resistance and combustion properties of aluminum powder by modification of nickel and dopamine
To improve the interface incompatibility, poor corrosion resistance, and limited combustion efficiency of aluminum powder for propellant applications. The surface of the naked aluminum was coated with a layer of dense nickel of about 100 nm by replacement method. A polydopamine film was then deposited by self-polymerization. The double-layer structure and chemical composition were investigated. The polydopamine content of composite particles was 2.3% by thermal analysis. And its heat release around 1050 C reached 4137 J g-1, which was much higher than that of aluminum of 1644 J g-1. The surface energies was used to calculate the theoretical adhesion work of aluminum and composite particles to propellant binder. The adhesion work after modification was increased from 62.33 mN m-1 to 74.89 mN m-1. No matter in the weak acid/alkaline or neutral environment, the composite particles exhibited excellent stability at 50 C. In addition, the combustion test revealed that the composite particles had higher combustion efficiency, smaller condensed phase product size, and stronger ignition ability. All the conclusions indicate after modification by nickel and dopamine, the comprehensive performance of aluminum is improved, and it may be used as an energy component in propellants or other energetic fields.