Ionic cocrystals (ICCs) hold significant potential to enhance performances for inorganic salts in fields of pharmaceuticals, photoelectricity, energetic materials, etc. However, the targeted design of ICCs with specific properties remains challenging. Herein, this work addresses the critical hygroscopicity of ammonium dinitramide (ADN), a vital green replacement for ammonium perchlorate (AP), by establishing the cooperative heterosynthon strategy. Specifically, improved binding energy in the cluster analysis revealed that moisture sensitivity originates from synergistic cation-anion interactions, which guided the identification of 3,4-diaminofurazan (DAF) as the optimal coformer through subsequent experimental screening. The resulting ADN/DAF cocrystal achieves unprecedented moisture resistance (critical relative humidity = 84.0% at 25 °C) among all ADN cocrystals, enables substitution for AP even surpassing ADN in specific impulse (272.25 s), and significantly enhances safety performance. Notably, this cocrystal demonstrates superior manufacturability: utilizing commercially available coformers and synthesizing via continuous flow production at the hectogram-scale with >88% yield. Therefore, this work presents an effective strategy for engineering moisture-resistant ionic cocrystals as well as showcasing high potential in applications for green energetic propellants.

Preparation of ammonium dinitramide spherical particles with improved anti-hygroscopicity performance by a low-temperature safe process

ABSTRACT The phase‐pure synthesis of the energetic cocrystal [NH 4 ] + ● [N 3 O 4 ] − ● [C 2 H 4 N 4 O], namely 3,4‐diaminofurazan C 2 H 4 N 4 O (DAF) and ammonium dinitramide (ADN) in the molar ratio 1:1 from an ethanol solution is reported. Its characterization by spectroscopic and thermal stability measurements as well as its crystal structure (space group Pbca , a = 7.046 Å b = 12.428 Å c = 19.649 Å) were obtained. The cocrystal shows an improved thermal stability (melting point peak temperature 127°C vs. 93°C ADN) and better insensitivity towards mechanical stimuli compared to pure ADN. Upon heating, the material shows no decomposition reactions up to 135°C, in contrast to the strong, self‐accelerating decomposition reactions in pure ADN at approximately 65°C and 115°C. The cocrystal enables improved dinitramide‐based energetic formulations and new coating possibilities for ADN prills. In combustion experiments with glycidyl azide polymer (GAP) based formulations, the cocrystal shows 2.5 to 5 times faster regression rates compared to carbamoylguanidinium dinitramide and nitroguanidine.

Ammonium dinitramide (ADN) is a promising, environmentallyfriendlyoxidizer for next-generation solid propellants. However, its highhygroscopicity and sensitivity to mechanical stimuli significantlyhinder its practical applications. Here, ADN–polymethylhydrosiloxane(ADN–PMHS) composite microspheres were prepared via solvent–antisolventcrystallization, followed by a simple surface coating step. The morphology,chemical structure, thermal behavior, hygroscopicity, and mechanicalsensitivity of the coated microspheres were systematically characterized.Results revealed that PMHS formed a uniform, continuous hydrophobiclayer on the ADN crystal surfaces, yielding well-dispersed sphericalparticles. At an optimal PMHS content of 0.5 wt % (ADN–0.5%PMHS),the composite exhibited 54.8% lower moisture uptake after 25 h at60% relative humidity and a 1.6 times reduction in impact sensitivitycompared with raw ADN. Moreover, the activation energy increased from164.44 to 184.96 kJ/mol, indicating improved thermal stability, whilethe decomposition temperature remained nearly unchanged. These findingsdemonstrate that ADN–0.5%PMHS microspheres possess enhancedmoisture resistance, mechanical insensitivity, and thermal stability,making them highly attractive for advanced, environmentally sustainablesolid-propellant formulations.

Numerical Investigation of Droplet Impact Dynamics of Ammonium Dinitramide (ADN)- Based Liquid Propellant on Solid Surfaces

An atom- and step-economical electrochemical method for the synthesis of aliphatic nitro-NNO-azoxy compounds from the corresponding nitroso compounds was developed employing ammonium dinitramide, a prospective green oxidant for aerospace propulsion applications, as both electrolyte and source of a =NNO2 group. The developed method is green, practical, and scalable due to constant current electrolysis in an undivided cell at high current densities. Synthesized products demonstrated pronounced NO-donor activity and fungicidal activity against phytopathogenic fungi.

Biomimetic confined synthesis of copper-enriched polydopamine single-atom catalyst for synergistic catalysis of ammonium perchlorate and ammonium dinitramide decomposition

Metal coordination interfacial enhancement effect: A strategy to fabricate low hygroscopic composite based on ammonium dinitramide (ADN) and polyether with enhanced mechanical properties

ABSTRACT Ammonium dinitramide (ADN) is a nitroamine explosive with high oxygen balance, high gas production and high energy, which can replace ammonium perchlorate (AP) in hydroxyl-terminated polybutadiene (HTPB) composite propellant to improve the energetic properties. We analyzed the performance of HTPB composite propellant with different ADN contents by studying the energetic properties, thermal decomposition behavior, combustion properties and condensed combustion products. With the increase of ADN content from 0% to 15% in HTPB composite propellant, the experimental combustion heat and theoretical specific impulse increase from around 6737 kJ/kg and 263.40 s to 7487 kJ/kg and 265.51 s, respectively. The burning rate of the propellant increases from around 7.6 mm/s to 8.5 mm/s at 7 MPa, and the burning rate-pressure exponent also increases from around 0.32 to 0.43 at 5 ~ 9 MPa. During the combustion of HTPB composite propellant containing ADN, a molten layer containing molten binder and molten ADN is formed on the combustion surface. The molten layer makes some aluminum particles agglomerate, and the aluminum agglomerates are taken away from the combustion surface by the combustion gas. With the increase of ADN content, the thickness of the molten layer increases, but the combustion gas production also increases at the same time. Therefore, with the increase of ADN content, the aluminum agglomeration on the combustion surface is firstly aggravated by the molten layer, and then inhibited by combustion gas, so the particle size of the aluminum agglomerates first gradually increases from around 27.07 μm to 54.66 μm and then no longer increases. The residual aluminum content of condensed combustion products first increases and then decreases with the increase of ADN content, which is related to the oxygen balance of propellant, aluminum agglomeration and crystal form of condensed combustion products. Novelty and Significance: As a nitroamine explosive with high oxygen balance different from RDX, ADN should have a wide application prospect in HTPB composite propellant after solving the problems of hygroscopicity and incompatibility with isocyanate. However, there are few explanations about the combustion phenomenon and mechanism of HTPB composite propellant with different ADN contents, so this paper studies the combustion of HTPB composite propellant with different ADN contents. According to the combustion phenomenon of HTPB composite propellant with different ADN contents, we discussed the influence of ADN content in HTPB composite propellant on the combustion and aluminum agglomeration based on the existing HTPB composite propellant combustion model.

First-principles study of hydrazinium nitroformate and Copper(I) 5-nitrotetrazolate: Eco-friendly substitutes for ammonium dinitramide and lead azide

Ammonium dinitramide (ADN) has emerged as a promisingsubstitutefor ammonium perchlorate (AP) in solid rocket propellants due to itsfavorable energetic properties and absence of halogens. However, acomprehensive understanding of its synthesis mechanism has not beenthoroughly achieved. In this sense, this study explores various submechanismsgoverning the synthesis of ADN in the gas phase and under the influenceof an implicit solvent (PCM). Density Functional Theory (DFT) wasemployed to determine the thermochemical properties of all stationarystates on the ground-state potential energy surface related to theelementary reactions involved in the nitration process. Five differentpathways were described for the gas phase reaction and three differentpathways with implicit solvent, all of which were accessible. Twoof the five pathways (the same two pathways found with PCM) appearto be preferential, forming nitramide more easily and favoring theformation of dinitramidic acid (HDN), which will later react withammonia to form ADN.

ABSTRACT Ammonium dinitramide (ADN) is gaining recognition as a promising “green” oxidizer for solid propellants, largely because it avoids the toxic chlorine by products produced by traditional agents like ammonium perchlorate (AP). However, ADN’s adoption is hampered by concerns about its thermal instability, which poses risks during storage and handling. In this study, we explored ways to enhance ADN’s stability by blending it with small amounts (1.5%) of two stabilizing agents: hexamethylenetetramine (HEX) and N-methyl-4-nitroaniline (MNA). Using differential scanning calorimetry (DSC) to simulate heating up to 270 °C, we found that both stabilizers noticeably increased the temperature and energy required for ADN to begin decomposing. This improvement suggests the additives disrupt the autocatalytic processes that usually lead to rapid degradation, directly addressing a major safety challenge. By slowing down the breakdown, these stabilizers not only make ADN safer to store and use but also broaden its application potential, whether in agricultural products or advanced energetic materials. Ultimately, this research highlights how a careful choice of stabilizers can transform ADN into a more reliable and eco-friendly option for future propellant and explosive formulations.

ABSTRACTThe thermal decomposition of ammonium dinitramide (ADN)‐based liquid propellant (ALP), which is composed of 63.4% ADN, 25.4% H2O, and 11.2% CH3OH by mass fraction, is significantly influenced by nitrogenous gases. To get a better insight into the effect of nitrogenous gases (N2, NH3, and NO2) on the thermal decomposition of ALP, the reactive force field ReaxFF‐lg was employed to describe the bonding and debonding of ALP. Three models (ALP/N2, ALP/NH3, and ALP/NO2) have been constructed to study the reaction pathways, main products, as well as the influences on mechanisms in the thermal high‐temperature decomposition of ALP at 1000–2500 K. The N─N bond in N2 was hardly broken to participate in the thermal high‐temperature decomposition of ALP. NH3 inhibited the decomposition of •NH4 in ADN, while NO2 enhanced the dehydrogenation of NH3 and then accelerated the thermal decomposition of ADN. NH3 facilitated the generation of H2O and reduced the number of •H and •OH, whereas NO2 inhibited the generation of H2O. NO2 promoted the decomposition of CH3OH to produce CO2 at high temperatures. This study provided an atomic mechanism for the decomposition process of ALP/gases, which would be helpful for further studies on the reaction mechanism of energetic fuels.

Effect of typical copper-based catalysts on the thermolysis and combustion behavior of high-energy oxidant ammonium dinitramide

Laser propulsion is a new conceptual technology that drives spacecraft and possesses advantages such as high specific impulse, large payload ratio, and low launch cost. It has potential applications in diverse areas, such as space debris mitigation and removal, microsatellite attitude control, and orbital maneuvering. Liquid pulse laser propulsion has notable advantages among the various laser propulsion systems. We review the concept and the theory of liquid laser propulsion. Then, we categorize the current state of research based on three types of propellants—non-energetic liquids, energetic liquids, and liquid metals—and provide an analysis of the propulsion characteristics arising from the laser ablation of liquids such as water, glycidyl azide polymer (GAP), hydroxylammonium nitrate (HAN), and ammonium dinitramide (ADN). We also discuss future research directions and challenges of pulsed liquid laser propulsion. Although experiments have yielded encouraging outcomes due to the distinctive properties of liquid propellants, continued investigation is essential to ensure that this technology performs reliably in actual aerospace applications. Consistent results under both spatial and ground conditions remain a key research content for fully realizing its potential.

Ammonium dinitramide (ADN)-based hydroxyl-terminated polybutadiene (HTPB) propellant prepared by dimeryl diisocyanate (DDI)

Effect of ammonium nitrate doping on the low-temperature thermal stability of ammonium dinitramide

The development of environmentally friendly propellant technology has become a primary focus in the defense industry. Composite propellants, which have traditionally relied on Ammonium Perchlorate (AP), offer high performance but pose environmental concerns due to the emission of corrosive chlorine compounds. This study aims to evaluate the potential use of green oxidizers such as Ammonium Dinitramide (ADN), Hydrazinium Nitroformate (HNF), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) as alternatives to AP. A qualitative literature review method was employed, drawing from various national and international scientific sources. Findings show that ADN and HNF offer promising performance and are more eco-friendly due to no chlorine emissions. However, challenges like thermal stability, hygroscopicity, and high production costs remain. This research highlights the potential of green oxidizers to reduce pollution and enhance national defense industry sustainability.

In recent years, there has been a resurgence of scientific interest in polynitrogen energetic materials. The considerable number of nitrogen bonds contributes to a high formation heat, and their low carbon and hydrogen content results in a good oxygen balance. The main decomposition product is nitrogen and that turns them into environmental-friendly energetic materials attracting research and investment. Very promising chlorine-free oxidizer is Ammonium dinitramide (ADN). In addition to its excellent performance and low ecological impact, this innovative oxidizer provides tactical advantages by eliminating primary metal oxide smoke and secondary aerosol smoke from condensed water vapor and exhaust products. Mitigating the risk of detection, reduction in corrosive combustion products and low flame temperature define Ammonium dinitramide as high energy eco-propellant and pyrotechnic igniter for rocket fuels. The minimized smoke output and reliable combustion characteristics make it well-suited for high-acceleration tactical missiles and underwater propulsion systems. Nevertheless, the high hygroscopicity of Ammonium dinitramide is a property severely influencing the hazards and safety of this promising energetic. To prevent ADN from absorbing moisture during handling, storage and processing the relative humidity of the environment should be below 55% [1]. Beyond its hygroscopic nature, ADN is also known to be incompatible with isocyanates, leading to spontaneous reactions and decomposition. To address the challenges associated with ADN and facilitate its production and application, the research community employs innovative methods. There are ongoing studies investigating the most efficient ADN particle form. The research discovers the utilisation of different polymers to lay uniform ADN particle coating thus improve the absorption of ambient humidity. This paper presents a summary of recent advancements in ADN improvement methods aimed at enhancing stability. Successful solutions for anti-hygroscopicity method are essential for the future application. Tests are being conducted to enhance the conditions of the ADN synthesis for scalable production.

ABSTRACTThe aerospace industry is continually seeking materials that offer higher performance and lower environmental impact. In chemical propulsion, ammonium dinitramide (ADN) represents a significant advance in this direction as a potential replacement for ammonium perchlorate in solid propellant formulations. Additionally, ADN has a promising application as a monopropellant. Known since the end of the 1980s, the synthesis of ADN still presents some challenges such as high cost, low yield, and high hazard. This scenario motivates continuous studies in the search for alternative and more advantageous routes. This work aims to study and improve two intermediates of ADN, namely potassium sulfamate (PS) and nitronium salt, focusing on obtaining high yield and lower hazard. It was possible to synthesize and characterize intermediates with considerable yield (∼90% to PS and ∼70% to nitronium trifluoroacetate) to be used in the follow‐up steps of the ADN synthesis. Complementary molecular quantum chemistry calculations were employed to evaluate the molecular properties of the intermediates.