The present disclosure relates to the handling of chemical warfare agents and more particularly, the present disclosure is directed to compositions and methods for detoxifying chemical warfare agents.
Destruction of bulk quantities of chemical warfare agents (CWAs) such as organophosphorous nerve agents including, but not limited to, G- and V-series nerve agents, and HD sulfur mustard is an urgent concern. Stockpiles of CWAs may be encountered by warfighters and civilians and poses a serious threat to individuals and the environment. CWAs are often found in containers of varying form, function and size, and typically under hostile environments.
Metal materials have been used to hydrolyze chemical warfare agents. However, these metal catalysts have been used in bulk amounts greater than 50% by weight levels when being exposed to chemical warfare agents so the use of these metals for bulk detoxification has not been feasible in the field when warfighters encounter chemical warfare agent stockpiles.
The present disclosure provides the capability to destroy quantities of CWAs, and in accordance with example implementations, a hydrolytic, doped-metal oxide catalyst that can be used either as a tactical additive to destroy bulk CWAs in-place in permissive and non-permissive environments, or as a modular cartridge format to destroy munitions or bulk storage containers of nerve and mustard CWAs in a flow-through approach. In accordance with example embodiments, the compositions and/or methods of the present disclosure may be scalable from a small, single munition to bulk barrel to fit the tactical mission but may further be scalable as an external recirculation platform to destroy very large CWA stockpiles in-place by adapting the cartridges to a pump and external cartridge manifold.
The present disclosure provides compositions and methods for detoxifying chemical warfare agents that may be used in the field by the warfighter.
Doped metal oxide compositions are provided that consist essentially of: fluoride; alumina; and less than 10% H2O.
Detoxification reactions are provided that can include a mixture of less than 50% by weight doped metal oxide composition and chemical warfare agent.
Cartridges are provided that can include a doped metal oxide composition, the composition including: fluoride and alumina.
Methods for detoxifying a chemical warfare agent are also provided. The methods can include exposing the chemical warfare agent to a doped metal oxide composition, wherein the doped metal oxide composition is less than 50% by mass of the chemical warfare agent.
Embodiments of the disclosure are described below with reference to the following accompanying drawings.
This disclosure is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
The present disclosure provides compositions and methods that can take the form of a cartridge that may be part of a kit that includes doped metal oxide nanoparticles; the metal oxide can include potassium fluoride (KF)-doped aluminum oxide (Al2O3) nanoparticles (KF/Al2O3). The doped nanoparticles may act as a ‘super-base’ to perform heterogeneous catalytic detoxification of G- & V-series nerve agents, and HD sulfur mustard. Unlike prior use of metal oxides, the present compositions and methods can utilize the chemical agent as the bulk of the reactor (at 90 weight percent, for example), while maintaining metal oxides at or below 10 weight percent.
In accordance with example implementations, the compositions and methods of the present disclosure can include one or more of the following features: (1) Provide doped metal oxides impregnated with potassium fluoride at a sufficient percentage to perform kinetic decomposition of CWA and their simulants; (2) Provide kinetic destruction of CWA and their simulants when added at 10 wt % or less.
Example CWA's and simulants that are amenable to detoxification using the compositions and methods of the present disclosure can include, but are not limited to: i. VX (simulant DiethylVX (DEVX), V-series); ii. and iii. Sarin (GB) (simulant Diisopropylfluorophosphate (DFP), G-series); (simulant Dimethyl methylphosphonate (DMMP), G-series); and/or iv. Sulfur Mustard (simulant 2-Chloroethyl ethyl sulfide (2-CEES), HD)
Current catalysts struggle in bulk chemical settings due to harsh conditions of the products, including strong acids or thiols, which can severely degrade catalytic performance.
With reference to
In accordance with example implementations, the compositions can be prepared by calcining the metal oxide. For example, using a precision scale, weigh out 375 grams of alumina in to high form crucibles. Place the crucibles containing the alumina in a chamber furnace; turn the furnace on and ramp the chamber temperature to 800° C. at a rate of 5° C./minute. An example chamber furnace can include Carbolite CWF-1100, Model CWF 11/23. Allow the temperature to dwell at 800° C. for 24 hours. After 24 hours, allow the furnace to cool to ambient temperatures; remove alumina and place in desiccator cabinet (desiccator cabinet set to 17% RH with Nitrogen, for example, TDI International #486D), to protect from ambient humidity. Alumina sources can include but are not limited to: alumina, gamma—American Elements; alumina, transitional—Panadye; alumina—Aldrich; alumina super 1—Aldrich; alumina, basic—Aldrich; alumina, neutral—Aldrich; alumina, acidic—Aldrich; alumina, nano—Aldrich; alumina—Nanophase; alumina, nano-arc—Alfa Aesar; alumina, gamma-phase—Alfa Aesar; alumina, alpha-phase—Alfa Aesar; alumina, nanotek—Alfa Aesar.
The dopant can also be prepared in accordance with example implementations. For example, a fluoride solution can be prepared by adding 1.406 L de-ionized water to a 2 L beaker, add a stir bar and place on a magnetic stir plate. Turn the stir plate on to provide adequate mixing and add fluoride to 250 g fluoride. Once dissolved, transfer the fluoride solution to a 4 L evaporating flask (for example, Buchi 4 L evaporating flask #047990). Fluoride sources can include but are not limited to: tetra-n-butylammonium fluoride; potassium fluoride; silver fluoride; and/or sodium fluoride.
Doping the metal oxides can include, for example, slowly adding 375 g calcinated alumina, to the 4 L evaporating flask containing the fluoride solution; swirl the flask after each 75 g addition of alumina to ensure an even mixture. This mixture will be a slurry. Once all the alumina has been incorporated into the fluoride mixture, place the evaporating flask onto the rotary evaporator. The rotary evaporator should be set to NO VACUUM. Lower the evaporating flask into the water bath, before starting the rotary evaporator, turn the rotary evaporator on and allow to incorporate for 24 hours.
Water can be removed from the doped composition by turning off the rotary evaporator, raising the evaporating flask from the water bath and adjusting the parameters to initiate the removal of water. The removal of water can take approximately 8 to 9 hours. The volume of water that is collected in the collection flask should be monitored to determine when the evaporation is complete. An example model rotary evaporator used can include Buchi, Model R-300, Interface I-300, Recirculating Chiller F-305, Vacuum Pump V-300, Heating Bath B-300 Bath.
After water removal, doped metal oxides are dried in the chamber furnace for 24 hours at 160° C. Remove the metal oxide powder from the 4 L evaporating flask and record the weight of the powder that is removed. Recovery is typically 90%+/−5% (562.5 g+/−31.25 g). The doped metal oxides should be aliquoted in high form crucibles and placed in a chamber furnace. The chamber furnace temperature should be ramped from ambient to 160° C. at a rate of 5° C./minute. Once the temperature is met, dwell at 160° C. for 24 hours. After 24 hours, allow furnace to cool to ambient temperatures before removing metal oxides. The doped metal oxides should be removed and stored in desiccator cabinet to limit exposure to oxygen and ambient humidity.
With reference to
In accordance with example implementations and as referenced above, the present compositions may act as a ‘super base’ for the destruction of organophosphorous nerve agents and mustard agents, circumventing much of the product inhibition challenge. While the compositions have been demonstrated to destroy chemical agents such as organophosphorus nerve agents and mustard agents, they can also be utilized to destroy chemical agent precursors. Chemical agents in stockpiles are frequently stored as binary components which are significantly less toxic to handle compared with the actual agent. When combined, they are mixed to form the agent. This is common in many types of munitions. One example is for sarin gas, which has a precursor, methylphosphonyl difluoride (DF), that can also be readily reacted with the doped metal oxides in order to render the DF precursor unable to be converted to sarin (GB) when combined with another binary precursor material. This is just one example that is representative of many known in the literature whereby chemical agent compounds can be stored as binary precursor components.
In accordance with example implementations, a cartridge 28 is provided that can include doped metal oxide composition 10. Cartridge 28 can include a main housing 29 and operable inlet 50 and exit ports 51. Accordingly, the cartridge can be configured as a flow through cartridge. In accordance with other implementations and in reference to
Cartridge-based methods for catalytic reactions have demonstrated increased efficiency and catalytic rate over their bulk dispersion counterparts. In addition, there are significant logistical gains in the transportation, operation, scaling, and waste disposal of such a modular design. The catalytic system, which is easily scalable, can provide improved capability over existing chemical destruction methods by providing a single solution to address the destruction of CWAs of varied size and container type in tactical environments. The potential application space is illustrated in
The compositions and methods of the present disclosure can provide at least two types of capabilities. In the first, additive kits including the doped metal oxide composition in a housing that can be added to a single container as shown (
With the second approach, a modular cartridge-based system 55 can be provided. Methods for detoxifying chemical warfare agents are provided using these cartridges. For example, the methods can include exposing the chemical warfare agent to a doped metal oxide composition, wherein the doped metal oxide composition is less than 50% by mass of the chemical warfare agent. This can be performed using the modular or kit-based systems. For example, the exposing can include adding the doped metal oxide composition to a vessel containing the chemical warfare agent as depicted in
In accordance with other implementations, the exposing can include providing the chemical warfare agent through at least one housing 29 containing doped metal oxide composition 10. The housing can be configured as a cartridge. The mass of chemical warfare agent provided through the housing can be greater than 50% of the mass of the doped metal oxide composition within the one housing and/or as high as 90%.
The method can also include, providing another housing 39 containing the doped metal oxide composition. The exposing can include providing the chemical warfare agent through both housings containing the doped metal oxide composition. As shown in
In accordance with example implementations and with reference to
Example compositions and/or methods of the present disclosure can be configured, and to perform, as indicated in Table 1 below.
The metal oxide catalysis technology will be adapted to a flow-through cartridge-based format to expand its destruction capabilities. The cartridge will be packed with doped metal oxides and through the use of an external pump or positive pressure displacement, agent will be pumped through the metal oxide cartridge. The cartridges can be hooked up to a fluidic pump source. External pumping approach is to invert the stoichiometry of the reaction; by pumping limited volumes of agent liquid through the external cartridge(s), the stoichiometric ratio of metal oxide particles to agent within the cartridge will vastly exceed 9:1 (v/v), thereby speeding up the reaction. This modular cartridge-based system wherein one or more metal oxide containing cartridges can be connected in series or in parallel via a manifold can be utilized to rapidly destroy agent volumes of varying size. Cartridge-based methods for catalytic reactions have demonstrated increased efficiency and catalytic rate over their bulk dispersion counterparts in terms of the conversion rate per catalyst weight. In addition, there are significant logistical gains in the transportation, operation, scaling, and waste disposal of such a modular design.
Additionally, with reference to
The compositions and methods can also include an access device and fluidics delivery system which will be required for operation of both the dispersive and modular cartridge approaches as shown in
Compositions and methods of the present disclosure can also be used to detoxify WMDs within 12 hours. Using external catalysts in flowing systems as shown in
The compositions and methods of the present disclosure were thoroughly tested against nerve-agent simulants in-house. Diethyl VX (DEVX, V-series) and Diisopropylfluorophosphate (DFP, G-series) have been utilized as simulants for nerve agents. Bulk reactors containing 90 wt % simulant and 10 wt % KF/Al2O3 were incubated at ambient temperatures. After various time points, aliquots were removed, extracted and analyzed via GC-MS to determine the amount of simulant that was destroyed by metal oxide nanoparticles. Several reaction conditions were tested: 1. Stagnant (no mixing) and no supplemental water; 2. Stagnant and 5% supplemental water added; 3. Mixing and no supplemental water; and 4. Mixing and 5% supplemental water added. In condition 2 and 4, where 5% supplemental water was added, the amount of KF/Al2O3 was reduced to 5 wt %, the additive total remained at 10%, with bulk simulant at 90 wt %.
With continued incubation time, the rates of DFP destruction increase as shown in
The compositions and methods were live-agent tested with sarin (GB) at and the data shown in
The compositions and methods were also tested for potential to destroy bulk VX agent. The compositions were exposed to VX at a 90:10 (v/v) agent: additive ratio. After 24 hours, 40% of the VX was detoxified (versus only 10% control with water added).
The potential enthalpy of mixing, and potential heat/pressure buildup by adding water and KF/Al2O3 to bulk dimethyl methyl phosphonate (DMMP, a G-series simulant) was also evaluated. Additives (KF/Al2O3 and water) were combined at 10 wt % to 90 wt % DMMP in a 5-gallon mock barrel. The addition of bulk water caused an immediate 6° C. temperature increase which gradually reduced within ten minutes. The bulk heat capacity of the liquid dissipates the enthalpy of mixing sufficiently that it is not a concern; addition of doped metal oxides with supplemental water or base cause no potential issues of increasing heat or pressure to a bulk-agent container.
The destruction of bulk G- & V-series nerve agent simulants DFP and DEVX can be optimized, and the efficacy with the HD mustard simulant 2-chloroethyl ethyl sulfide (2-CEES), half-mustard demonstrated.
Additionally, scaling of the destruction kinetics with simulant volume has been demonstrated at the 10-mL, 100-mL, 1-L and 10-L scale with DMMP (
In accordance with example implementations, bulk reactors containing 90 wt % CWA (simulant) and 10 wt % KF/Al2O3 and allowed to react at ambient temperatures. The data of
To improve destruction kinetics, the reactions were scaled to 1 mL, and active mixing (via a magnetic stir-bar and stir plate) was added. Bulk reactors containing 90 wt % DFP, DMMP or DEVX and 10 wt % KF/Al2O3 were incubated at ambient temperatures in 1 mL glass vials and kept stirring at 250 rpm for the duration of the experiments. To date we have demonstrated that after a 24-hour incubation approximately 63% of each simulant is destroyed; after 48-hours approximately 75% of each simulant is destroyed, and after 1-week almost all simulant is destroyed by the doped metal oxide compositions.
To ensure the destruction kinetics scaled to larger volumes, DMMP was utilized to scale from 1 mL to 10 L. At all scales simulant: additive ratio was 90:10. Reactions volumes: scale from 1 mL, 10 mL, 100 mL, 1 L and 10 L. In all cases the rate of destruction remained the same or increased with larger volumes of DMMP. To date we have demonstrated that 66% of DMMP is destroyed after 24 hours, 79% of DMMP is destroyed after 48 hours and after 1 week>99% simulant is destroyed by the doped metal oxide compositions.
The compositions and methods of the present disclosure were live-agent tested with sarin (GB) organophosphorus nerve agent to identify chemical weapons in samples. When the metal oxide was added to GB at a 90:10 (v/v) agent: metal oxide ratio, 96% GB was destroyed in 72 hours. Through the addition of supplemental water (up to 10%) the destruction kinetics of GB increased, and 100% destruction was achieved by 72 hours.
The compositions and methods of the present disclosure were also tested for potential to destroy bulk VX agent. The metal oxide composition was added to VX at a 90:10 (v/v) agent: additive ratio. After 24 hours, 40% of the VX was detoxified (versus only 10% control with water added).
The concentration of the fluoride of the composition metal oxide can be varied from 20% to 80% by weight. Varying the amount of fluoride may affect the kinetic rate of agent destruction and is specific to both the agent type and dope composition. As shown in
In compliance with the statute, embodiments of the invention have been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the entire invention is not limited to the specific features and/or embodiments shown and/or described, since the disclosed embodiments comprise forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.
This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 62/738,302 filed Sep. 28, 2018, entitled “Compositions and Methods for Detoxifying Chemical Warfare Agents”, the entirety of which is incorporated by reference herein.
This invention was made with Government support under Contract HR0011-14-C-0030 awarded by the Defense Advanced Research Projects Agency (DARPA). The Government has certain rights in the invention.
Number | Name | Date | Kind |
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7598199 | Hatton et al. | Oct 2009 | B2 |
7678736 | Wagner | Mar 2010 | B1 |
20090216060 | Monzyk | Aug 2009 | A1 |
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Number | Date | Country | |
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62738302 | Sep 2018 | US |