(517a) Dissipative Particle Dynamics Simulations of Nanopowder Dispersion for Applications in Solid Propellants

Metal nanoparticle addition into solid propellants has potential to significantly improve performance, but poor control over the final microstructure of the propellant has so far greatly limited practical applications. Here we present a computational and experimental study of nanoscale mixing processes to understand the processing-dispersion relationship of nanoscale metal fuel in composite propellants. We use multiscale simulations informed from experimental mixing conditions and compare final microstructure with microstructures obtained from experiments via SEM. We find that increasing nanoparticle volume fraction increases tendency for agglomeration. We also describe the effect on this tendency produced by altering the interaction between nanoparticles at constant agitation amplitude. The dissipative particle dynamics model capture the basic mechanisms retarding dispersion at higher mass fraction of nanoparticle filler, and indicate the degree of surface treatment of nanoparticles needed in order to achieve dispersion. These studies provide guidance to further improve incorporation of nanoparticle into propellants formulation and have direct applicability to more complex propellant systems. The methodology presented here could be applied to any mixing of nanopowder into highly viscous matrices.

Authors acknowledge support from Armament Research, Development and Engineering Center, Picatinny Arsenal. Work is performed under DOD SBIR program.