Iodine Pentoxide Nano‐rods for High Density Energetic Materials

Abstract

The iodine pentoxide is one of the most advanced oxidizers for nanostructured energetic formulations among the thermites due to the highest energy release per volume 25.7 kJ cm À3 . The size and shape of iodine pentoxide particles have a strong impact on the pressurization rates during the reaction. Although micro-sized iodine pentoxide particles are commercially available, nano-sized particles, which are desired for various nano-energetic applications, are not available on the market. Conventional wet chemical methods are unable to produce iodine pentoxide nanoparticles due to high solubility in water. In this study, we demonstrate fabrication of iodine pentoxide nano-rods by high energy mechanical treatment of microsized I 2 O 5 particles. Tuning the energy dose in high-energy ball milling is allowing to produce I 2 O 5 nano-rods with diameter of 50-100 nm and length of 300-600 nm. The produced nano-rods exhibited 10 % smaller decomposition energy compared to the precursor of micro particles. The experiments showed that the nano-energetic materials prepared with nano-sized I 2 O 5 rods have pressure discharge value of 43.4 MPa g À1 which is two times higher than using commercial iodine pentoxide particles.

Hydroxide‐Based Nanoenergetic Materials

“…Although thermodynamic calculations (see Figure 1) show that all four systems have comparable overall gas generation ability of 2.2-2.8 L g À1 , which includes all possible gases generated at highest adiabatic temperature and it appears that the lower boiling temperature of oxidizer metal is the most important factor for highest pressure discharge value. This observation agrees well with previously published results for AlÀI 2 O 5 system, where the boiling point of oxidizer element (iodine boiling point is 184.3 K) is much lower than the combustion adiabatic temperature 3830 K [20], resulting in extremely high normalized pressure 14.8 kPa*m 3 g À1 [21]. The calorimetric measure-ment of heat generation shows that AlÀNi(OH) 2 system has higher heat release ability than AlÀBi(OH) 3 system.…”

“…This size, being not very pyrophoric, is covered by approximately 4-5 nm aluminum oxide layer. The active content of Al is 87 % with oxide layer 13 % by mass [21], which was taken into account during preparation of the thermite mixtures. The Al nanoparticles can be safely mixed with oxidizers under hexane environment in rotary ball mill.…”

Tuning the Reactivity of Nano-energetic Gas Generators Based on Bismuth and Iodine Oxidizers

“…The particle size of iodine pentoxide was regulated by time controlling of high energy ball milling process via tuning the applied energy dose which is transferred to the milling media. The details of estimation of energy dose transferred to particles can be calculated using the method described in [12]. The total energy transferred per unit mass of powder, or the For the bismuth hydroxide, the mechanical treatment method is working similarly [28].…”

“…The class of compositions in thermites can be very diverse, where the metal powders act as a fuel, and the oxidizers are various oxides such as traditional metal oxides including Fe 2 O 3 , Co 3 O 4 , MoO 3 , etc [5][6][7]. Other highly powerful oxidizers include Nanoenergetic Gas Generators [2,8] constituents such as I 2 O 5 [9][10][11][12] and Bi 2 O 3 [13][14][15][16]. The metal fuel in thermites is usually aluminum powder, although occasionally magnesium is also utilized as a fuel metal [17].…”

Ignition and Combustion Characterization of Ca(IO3)2‐based Pyrotechnic Composites with B, Al, and Ti

“…However, direct addition of elemental iodine reduces the thermal output of the formulation because iodine is a passive agent [9]. In order to maintain high reactivity without compromising iodine content, different iodine-containing oxidizers such as I 2 O 5 , AgIO 3 , Ca(IO 3 ) 2 , Cu(IO 3 ) 2 , Fe(IO 3 ) 3 and Bi(IO 3 ) 3 have been explored [3,[13][14][15][16][17][18]. In addition, to their high iodine content, these oxidizers have a high enthalpy of reaction and high flame temperature when used as part of an Al-based pyrolant mixture (Table S1).…”