Preparation of sub-micron nitrocellulose particles for improved combustion behavior.

A novel method to prepare sub-micron nitrocellulose particles with spherical shape is demonstrated. The morphology of the nitrocellulose can be controlled by the solvent and the growth temperature. Using dimethylformamide (DMF) at a growth temperature is 5°C, reproducibly yielded spherical nitrocellulose particles. The final diameter of the prepared nitrocellulose particles can be further tuned by concentration. The smallest particles in this study were found to have diameters of 500nm at a concentration of 5-10mg/ml with 2 micron spheres formed at 30mg/ml. Furthermore, the thermal properties and the burn rates of the prepared materials are studied by differential scanning calorimetry and digital high-speed photography, respectively. In comparison to the bulk nitrocellulose material, the sub-micron nitrocellulose particles have lower decomposition activation energy, a 350% increase in burn rate, and a more complete combustion.