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10:52
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Interfacial interactions in CL-20/alloy-metal/polymer energetic composites: a molecular dynamics study.
Hao Wang1,2, Bohan Guo3, Yanyan Tan3
1School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210018, China. kulak@njust.edu.cn.
Journal of Molecular Modeling
|June 27, 2026
Summary
Molecular dynamics simulations reveal distinct interfacial adhesion hierarchies in polymer-bonded explosives (PBXs). Metal/wax interfaces show strongest cohesion, while CL-20/polymer interfaces are weakest, with alloying elements not improving adhesion.
Area of Science:
- Computational materials science
- Energetic materials
- Polymer-bonded explosives (PBXs)
Background:
- Interfacial interactions in PBXs are critical for mechanical integrity, processing, and safety.
- Limited systematic data exists for all three interface classes (energetic filler/binder, filler/fuel, fuel/binder).
- The effect of alloying metallic fuels on interfacial adhesion is unexplored.
Purpose of the Study:
- To comprehensively characterize interfacial adhesion and mechanical properties across 23 binary material combinations.
- To investigate the influence of alloying aluminum with Lithium (Li) or Boron (B) on interfacial adhesion.
- To establish a systematic comparative dataset for PBX interface design.
Main Methods:
- Molecular dynamics (MD) simulations using the COMPASS III force field.
- Interface models constructed using Materials Studio, geometry-optimized, and equilibrated under NVT ensemble.
- Calculated cohesive energy density, binding energy, and mechanical properties (elastic, bulk, shear moduli, Poisson's ratio).
Main Results:
- A three-tier hierarchy of interfacial strength was observed: Metal/wax > CL-20/metal > CL-20/polymer.
- Metal/wax interfaces exhibit strong cohesion (van der Waals dominated); CL-20/metal interfaces show intermediate binding (van der Waals/electrostatic); CL-20/polymer interfaces are weakest.
- Alloying aluminum with Li or B did not significantly enhance interfacial adhesion compared to pure Al. Ethylene-vinyl acetate (EVA) showed optimal CL-20 adhesion and stiffness, while ethylene-propylene-diene monomer (EPDM) offered superior ductility.
Conclusions:
- Interfacial interactions significantly influence PBX properties, with distinct strength hierarchies.
- Current alloying strategies for aluminum fuels do not improve interfacial adhesion with CL-20 or binders.
- Binder selection (EVA for balance, EPDM for ductility) is crucial for tailoring PBX performance.
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