Crystal Surface Engineering Strategy for ADN: Synergistic Spherical Granulation and MD-Guided Coating

Ammonium dinitramide (ADN), an eco-friendly oxidizer for propellants, offers high specific impulse but suffers from severe hygroscopicity, limiting its use. To address this, a stepwise “spherical granulation & Molecular Dynamics (MD) simulation-guided hydrophobic coating” strategy is presented. MD screened 12 hydrophobic materials for ADN coating compatibility. Experimental validation involved optimizing melt granulation stirring speed and viscosity, employing Fluorocarbon Surfactant FC-02 coating. The results indicate that MD simulations identified FC-02 as the optimal coating material, with an interaction energy of −1554.98 kJ/mol with ADN, dominated by electrostatic interactions. After optimizing melt granulation parameters, the ADN particle size decreased to 0.16 mm, with a sphericity reaching 0.819. Following FC-02 coating, the water absorption of ADN decreased to 0.39%, while maintaining stable energy performance, and friction sensitivity reduced by 16%, significantly enhancing safety. This study shows the synergistic mechanism of “spherical granulation and hydrophobic coating,” providing theoretical support for the engineering application of ADN in propellants.