Boron Carbide Based Biocide Compositions: A Study of Iodate Particle Size on Combustion and Iodine Output

Abstract

The ever‐present threat of biological weapons has encouraged the development of novel pyrotechnic formulations that release gaseous iodine upon combustion, which acts as a potent active agent capable of countering bio‐agents (e. g. anthrax). These formulations typically contain a fuel (Al, B, Al/B4C) and an iodate serving as an oxidizer. However, the percentage of free iodine generated is relatively low and aging of these formulations remains an issue. In this work, the role of particle size on the combustion velocities, iodine output, and combustion products are detailed for a boron carbide/sodium periodate formulation. Formulations are studied with and without the addition of binder (protectant) and the role of particle size on achieving 3‐D printable energetics is detailed. It is found that altering the fuel particle size (boron carbide) had little effect on the combustion velocity and iodine recovery. However, by reducing the particle size of the oxidizer, NaIO4, drastic improvements in iodine recovery are achieved. A reduction in mean particle size from 215 to 3 μm resulted in a 47 % increase in observed iodine recovery for powder formulations. Combustion velocities appear to be unaffected and were 1.4–1.6 mm/s. An in‐depth discussion of the decomposition pathway of pure NaIO4 as well as when paired with a B4C fuel source is also discussed.

Flexoelectricity in fluoropolymer/aluminium reactives

“…Al, B, Ti). 16 While fluoropolymers have been used as oxidizers in energetic materials, there has been limited research on how the electromechanical properties influence the combustion properties. [15][16][17][18] Specifically, tuning the impact sensitivity, burning rate and other combustion properties in fluoropolymer bound energetics by using piezoelectricity and flexoelectricity has yet to be fully studied.…”

“…16 While fluoropolymers have been used as oxidizers in energetic materials, there has been limited research on how the electromechanical properties influence the combustion properties. [15][16][17][18] Specifically, tuning the impact sensitivity, burning rate and other combustion properties in fluoropolymer bound energetics by using piezoelectricity and flexoelectricity has yet to be fully studied. Initial research by Row and Groven 15 reported a significant change in the impact sensitivity when a DC voltage was applied to the PVDF/Al and THV/Al reactive systems indicating the electroactive nature.…”

“…Multiple studies demonstrate additive manufacturing as a route to manipulate the structure of electroactive [19][20][21] and energetic materials. 16,22 It is plausible that by taking advantage of the precision and accuracy that additive manufacturing offers the flexoelectric effect may also be maximized through architectural design and structure. This is particularly exciting for energetic materials where controlled response is highly desired.…”

“…THV also has a 9% higher fluorine content than PVDF, which can enhance combustion properties when combined with appropriate fuels (e.g. Al, B, Ti) 16 …”

Nitrocellulose‐Based Green‐Light Illuminants: A Study of Barium Nitrate Particle Size on Spectral Performance

“…It is well known that the particle size of the reactive solids, whether the fuel or oxidizer, can greatly influence the overall system. While many studies have focused on the fuel particle size for pyrotechnic and propellant systems [1][2][3][4][5][6], few have studied the oxidizer particle size directly for use in pyrotechnics [7][8][9][10][11]. Overall, the consensus from the fuel studies is that as the fuel (aluminum, zirconium, boron, magnesium, etc.)…”