Aluminum nanoparticles have widely been used as fuel additives to solid propellants for rocket propulsion, but the formation of the oxide layer has been a setback for their application. A viable solution to this problem is to passivate aluminum (Al) with a layer of nickel (Ni), which offers multiple advantages. The current study focuses on energetic intermetallic interaction within Ni-coated Al nanoparticles and also the interaction/coalescence between two Ni-coated Al nanoparticles of varying sizes. Molecular dynamics (MD) method is employed to study the size-dependent variation of these interactions.

A thermodynamic formulation is devised to calculate the adiabatic reaction temperature of single as well as coated nanoparticles. The results obtained using this formulation are compared with the results obtained from MD simulations. The estimation of dead layer thickness formed at the interface of Ni and Al is critical to correctly capture the energetic behavior. In this work, the dead layer thickness is estimated and used to predict the adiabatic reaction temperature of the coalescence of two equal-/unequal-sized Ni-coated Al nanoparticles. It has been found that particle size can affect the adiabatic reaction temperature because of the varying surface energy. It has also been found that the dead layer thickness plays a vital role in accurately determining the adiabatic reaction temperature of the system. It has been observed that the reaction time decreases proportionately with increase in specific reaction surface area (between Al and Ni) for single as well as coated particles.

铝纳米颗粒已被广泛用作火箭推进器固体推进剂的燃料添加剂，但氧化层的形成已阻碍了其应用。解决此问题的可行方法是钝化带有一层镍（Ni）的铝（Al），这具有多个优点。当前的研究集中在镀镍的铝纳米颗粒内的高能金属间相互作用，以及两个不同尺寸的镀镍的铝纳米颗粒之间的相互作用/聚结。分子动力学（MD）方法用于研究这些相互作用的大小依赖性变化。

设计了一种热力学公式来计算单个纳米颗粒和涂覆纳米颗粒的绝热反应温度。将使用该公式获得的结果与通过MD模拟获得的结果进行比较。估计在Ni和Al的界面处形成的死层厚度对于正确捕获高能行为至关重要。在这项工作中，估算死层厚度，并将其用于预测两个相等/不等大小的Ni包覆的Al纳米颗粒聚结的绝热反应温度。已经发现，由于表面能的变化，粒径会影响绝热反应温度。还已经发现，死层厚度在准确确定系统的绝热反应温度中起着至关重要的作用。