(435f) The Role of Particle Size on the Combustion of Boron Carbide/Sodium Periodate Biocidal Formulations

The Role of Particle
Size on the Combustion of Boron Carbide/Sodium Periodate

Biocidal Formulations

Lance N. Kotter^a
and Lori J. Groven^b,*

^aSouth Dakota School of Mines and
Technology, Department of Material Science and Engineering, Rapid City, SD, US

^bSouth Dakota School of Mines and
Technology, Department of Chemical and Biological Engineering, Rapid City, SD,
US

*corresponding author email:
lori.groven@sdsmt.edu

Abstract

In our groups previous work, the boron
carbide/iodate system has been shown to be an effective biocidal agent.  The use of boron carbide mitigates aging
issues typically associated with traditional aluminum-based formulations.  In this work, boron carbide based biocidal
formulations with NaIO₄ serving as the primary oxidizer are explored
and the role of particle size on the combustion velocities, iodine output, and
combustion products are detailed. Formulations are studied with and without the
addition of binder and the role of particle size detailed toward developing 3-D
printable energetics. It was shown in this study that the effect of changing
the boron carbide particle size had negligible effects on both the combustion
velocity and iodine recovery. Ignition was however significantly influenced. However,
promising results have been established by reducing the particle size of the
oxidizer, NaIO₄. The NaIO₄ was milled to an D₉₀
value of 30.30µm resulting in iodine recovery close to 90%, much
higher than any formulation examined thus far. By reducing the particle
size even further to under 25 µm while maintaining the same fuel
content, iodine recovery was close to 100%.  Iodine quantification was done using UV-VIS, simultaneous
differential scanning calorimetry and thermogravimetric analysis (DSC/TGA),
heat of reaction, X-ray diffraction (XRD) and combustion characteristics will
be discussed as a function of oxidizer size.