Theoretical study on multi-perspective interaction analysis of ADN and ADN-H₂O-CH₃OH solutions

Area of Science:

• Computational chemistry
• Materials science
• Chemical engineering

Background:

• Understanding intermolecular interactions in ammonium dinitramide (ADN)-based liquid propellants is crucial for performance optimization.
• Previous studies have explored various aspects of ADN propellants, but a comprehensive atomic-level analysis of interaction mechanisms and their impact on performance is needed.

Purpose of the Study:

• To reveal the mechanism of intermolecular interactions in ADN and ADN-water-methanol solutions.
• To explore the reasons behind performance changes in these liquid propellants.
• To provide insights for the development of new liquid propellants.

Main Methods:

• Theoretical calculations including band structure, density of states (DOS), surface electrostatic potential (ESP), Hirshfeld surface analysis, reduced density gradient (RDG), and atoms in molecules (AIM) topological analysis.
• Construction and optimization of ADN and ADN-H2O-CH3OH solutions using Materials Studio (Amorphous cell module, Dmol3 module with GGA/PBE methods).
• Hirshfeld surface generation (CrystalExplorer 3.0), QTAIM analysis (Multiwfn 3.0), and RDG analysis (Multiwfn 3.0).

Main Results:

• Both ADN and ADN-H2O-CH3OH solutions exhibit hydrogen bonds and van der Waals interactions.
• Introduction of water (H2O) and methanol (CH3OH) led to a slight decrease in detonation performance but also a reduction in sensitivity.
• Comprehensive performance of the ADN-H2O-CH3OH solution improved, expanding its application range.

Conclusions:

• The study provides a detailed atomic-level understanding of intermolecular interactions in ADN-based liquid propellants.
• The findings suggest that modifying propellant composition with small molecules like water and methanol can balance performance and sensitivity.
• This research contributes to the rational design and development of advanced liquid propellants with enhanced properties.