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.

为提升铝粉在推进剂应用中的界面兼容性、劣质耐腐蚀性能以及有限的燃烧效率，本研究采用替换法在裸铝表面沉积了一层厚度约为100纳米的致密镍膜。随后，通过自聚合反应在其上沉积了一层聚多巴胺薄膜。对双层结构及其化学成分进行了深入研究。热分析表明，复合颗粒中聚多巴胺的含量为2.3%。其于1050°C附近的放热量达到4137 J g^-1，远高于铝的1644 J g^-1。利用表面能计算了铝和复合颗粒对推进剂粘合剂的理论粘附功。改性后的粘附功从62.33 mN m^-1 提升至74.89 mN m^-1。无论是在弱酸/碱性环境还是中性环境中，复合颗粒在50°C下均表现出优异的稳定性。此外，燃烧试验揭示复合颗粒具有更高的燃烧效率、更小的凝聚相产物尺寸以及更强的点火能力。所有结论均表明，通过镍和多巴胺的改性处理，铝的综合性能得到显著提升，有望作为推进剂或其他高能领域的能源组分。