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Studies on nitrocellulose (NC) mixtures with little solubilities were neglected in many cases previously. This investigation was performed to provide supplemental characterizations of NC and its soaked state with pure liquid ethanol or diethyl ether by simulations and practical methods. Above all, a short-chained NC model (polymerisation degree: 8) and a dried NC specimen were characterized for their substitution of nitrate and microstructure. It was confirmed that both the numerical model and practical specimen belonged to low-nitrated NC. The bonding information of a glycosyl unit and nitrate ester were summarized via first-principle calculations. Then, ReaxFF potential based Molecular Dynamic (MD) simulations and soaking tests on binary organic mixtures demonstrated that both ethanol and diethyl ether had limited solubility for our specified NC. However, potential energies and diffusion coefficients of both computational models showed that the interactions from ethanol molecules were relatively stronger than diethyl ether molecules. The viscosities of saturated NC solutions also proved this consequence, as the difference between pure ether and its filtered NC solution was only 0.02 mm2 s−1. Finally, the strong volatility of diethyl ether itself could keep the wetness of NC upper surface shortly, because this was an upward volatilization effect. Due to this effect, the penetration of NC-diethyl ether mixture was higher in the early period of penetration tests.

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Al nano-particle (ANP) have high reactivity, but they are easily inactivated by external oxidants. To improve its surface property, we coat ANPs with nitrocellulose (NC)/ethanol/ether solution. And MD simulation method is used to simulate the coating, ignition and combustion processes of ANPs under three different coating conditions. Our results show that the NC/ethanol/ether formed a dense coating layer on the surface of annealed ANPs and passivated ANPs through physical and chemical adsorption. The coating layer can block the contact between the active Al atoms and O2 molecules at low temperature. In ignition phase, NC/ethanol/ether coating layer can increase the density of O2 molecules around ANPs and the surface temperature of ANPs. At the same time, due to the desorption and diffusion of the coating layer exposed more reaction sites, ANPs have shorter ignition delay and lower ignition temperature. According to the change of atomic displacement, the combustion stage can be divided into three stages. The NC molecules can increase the combustion propagation speed, combustion time and efficiency of ANPs. Such improvement will enable ANPs to obtain better storage performance, combustion performance and play a stronger role in the field of energetic materials.

Aluminum (Al) nanoparticle (ANP), as a metal fuel agent, has excellent combustion rate and energy density. However, several critical research gaps of ANP still exist. This study is focused on the annealing properties of ANP and its coating performances under the mixture of ethanol and ether molecules. According to those obtained molecular dynamic (MD) simulation results, the microstructure of ANP in the annealing process and the formation of ethanol–ether binary coating are discussed in this paper. During the melting process, the melting point of ANP could be analyzed by the inflection point of its atomic potential energy and the mean square displacement, then the accuracy of EAM force field could be verified. Because surface atoms have lower potential energy than inner atoms, it seems that the melting of ANP started from the particle surface and diffuses from surface to the core. When the melted Al cluster is solidified until 300 K, the microstructure of the crystallized particle is largely affected by the cooling rate. If the cooling rate if too fast, it is not enough for the Al cluster to recrystallize, which is called as the “freezing effect” for ANP. Next, the binary “competitive adsorption” behavior of ethanol and ether on the surface of ANP was simulated according to different ethanol–ether molecular ratios. Analyses of ethanol–ether binary coating layer show that the main component of binary coating is ethanol, but not ether. This competitive superiority of ethanol is caused by its own adsorption mechanism and molecular migration in this mixture of ethanol and ether.