This invention relates to protection against chemical warfare agents and toxic industrial chemicals.
Chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) pose a severe human hazard.
In the prior art, carbon may be used in protective clothing, in filters, and the like. Activated carbon is a very good adsorbent of CWAs and TICs. One problem is that the carbon itself becomes contaminated.
Carbon-based systems are also quickly saturated since the carbon also absorbs relatively harmless chemicals such as exhaust gases and the like. Protective clothing including carbon is also heavy, cumbersome, and hot. See, e.g., U.S. Pat. No. 6,792,625, incorporated by reference herein.
Several metal-organic framework (MOF) materials are known and have been studied because of their porous nature. It has been suggested to use MOF materials for hydrogen storage. See, e.g., U.S. Pat. Nos. 6,929,679, and 7,343,747, both incorporated by reference herein. See also Chen, Ockwig, Millward, Contreras, and Yaghi, High H2 Absorption in Microporous Metal-Organic Framework with Open Metal Sites, Angew. Chem. Int. Ed. (2005) pp: 4735-4749 (disclosing MOF-505), incorporated by reference herein.
MOF materials, due to their high and permanent porosity, offer a potential substitute for carbon-based systems used in protective clothing and filters to protect people against CWAs and TICs.
The result in clothing, for example, would not become saturated as quickly, would be less heavy and cumbersome, and not as hot. But, known MOF materials do not chemically degrade CWA and TIC compounds.
It is therefore an object of this invention to provide new MOFs.
It is a further object of this invention to provide such MOFs which are self-decontaminating.
It is a further object of this invention to provide such self-decontaminating MOFs which can be used to protect people from CWAs and TICs.
This invention features a self-decontaminating metal organic framework which includes an acid linked to a metal producing a metal organic framework configured for the sorption of chemical warfare agents and/or toxic industrial chemicals. The metal organic framework includes reactive sites for the degradation of said agents and chemicals.
In one embodiment, the acid may be a triple bonded acid. The acid may be acetylenedicarboxylic acid (ADA). The metal may be copper nitrate. The self-decontaminating metal organic framework may be linked to the metal with a linking agent. The linking agent may include Pyrazine, 2,6-dimethylpyrazine, 2-6-dichloropyrazine, dipyridylethlene, 4,4′-dipyridyl, or 2,3,5,6-tetramethylpyrazine. The enzyme added to the metal organic framework to may assist in the degradation of said agents and chemicals. The non-self-decontaminating metal organic framework may be added to the self-decontaminating metal organic framework. The size of the pores of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals. The surface area of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals.
This invention also features a method for producing a self-decontaminating metal organic framework, the method including combining an acid with a linking agent and a metal to produce a self-decontaminating metal organic framework for sorption of chemical warfare agents and/or toxic industrial chemicals. The self-decontaminating metal organic framework may include reactive sites for the degradation of said agents and chemicals.
In another embodiment, the acid may be a triple bonded acid. The acid may be acetylenedicareoxylic acid (ADA). The metal may be copper nitrate. The linking agent may include Pyrazine, 2,6-dimethylpyrazine, 2-6-dichloropyrazine, dipyridylethlene, 4,4′-dipyridyl, or 2,3,5,6-tetramethylpyrazine. The method may include the step of adding an enzyme to the metal organic framework to assist in the degradation of said agents and chemical. The size of the pores of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals. The surface area of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals.
This invention further features a method of absorbing and degrading chemical warfare agents and toxic industrial chemicals, the method including adding a self-decontaminating metal organic framework to fabric or filter material, the self-decontaminating metal organic framework comprising an acid linked to a metal-organic framework for the sorption of chemical warfare agents and/or toxic industrial chemicals. The metal organic framework may include reactive sites for the degradation of said agents and chemicals.
In another embodiment, the acid may be a triple bonded acid. The acid may be acetylenedicareoxylic acid. The metal may be copper nitrate. The self-decontaminating metal organic framework may be linked to the metal with a linking agent. The linking agent may include Pyrazine, 2,6-dimethylpyrazine, 2-6-dichloropyrazine, dipyridylethlene, 4,4′-dipyridyl, or 2,3,5,6-tetramethylpyrazine. The method may include an enzyme added to the metal organic framework to assist in the degradation of said agents and chemicals. The size of the pores of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals. The surface area of the self-decontaminating metal organic framework may be tailored for specific said agents and chemicals.
The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives.
Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
There is shown in
SD-MOF 10′,
SD-MOF 10″,
SD-MOF 10′″,
SD-MOF 10IV,
In yet another design, SD-MOF 10v,
SD-MOF 10,
For example, one known simulant of a CWA is methyl parathion (MPT) 30,
Preferably, SD-MOF 10 of this invention is added to a fabric or filter material which may be used as protective clothing and/or filters and the like, to protect people from CWAs and TICs. Because SD-MOF 10 is self-decontaminating and reactive with CWAs and TICs, any protective clothing or filters made from it does not need to be replaced after one use. The protective clothing made from the SD-MOF of this invention is also lighter and less cumbersome than conventional protective clothing made with carbon or similar type materials.
In one embodiment, an enzyme, such as organophosphorous hydrolase (OPH) may be added to SD-MOF to assist in the degradation of CWAs or TICs. Other enzymes known to those skilled in the art may be utilized.
Non self-decontaminating metal organic frameworks may be added to SD-MOF 10 to further increase its porosity. The size of the pores of SD-MOF 10 may be tailored for specific CWAs and TICs, e.g., in the range of about 4 Å to about 12 Å. Similarly, the surface area of SD-MOF 10 may be tailored for specific CWAs and TICs. In one example, SD-MOF 10V,
The following examples are meant to illustrate and not limit the present invention.
Amine-based linker chemistries may be used to create SD-MOF 10 of this invention. This may be accomplished by combining pyridinyl amine linkers with linear acetylenedicarboxylic acid (ADA) and hydrothermally treating these chemicals in the presence of copper cations at 90-100° C. Examples of active pyridinyl amine linkers, or linking agents 16, are discussed above with reference to
Linking agents 16 can be utilized to alter adsorbent selectivity and activity of SD-MOF 10. SD-MOF 10 may be created though a chelating reaction in either water or a 1:1:1 mixture of N,N′-dimethyl formamide (DMF):methanol:water. Both techniques create a final SD-MOF 10 that shows activity against CWAs and TICs. Reactivity has been observed for both a liquid environment (e.g. a solution of MPT and MPO) and a gas environment (e.g. flowing a stream of nitrogen spiked with MPO vapors at ambient condition). Examples of the various embodiments of the SD-MOF of this invention are shown in
In one example, the chemical reactivity of one or more of SD-MOF 10,
The chemical activity of the SD-MOF of this invention towards MPT hydrolysis was observed using UV-VIS. The appearance of pNP was monitored immediately when 100 μmolar MPT solution was exposed to 100 mg of SD-MOF. It was noticed that the amount of pNP was less than 100% conversion, indicating the partial sorption of MPT to SD-MOF powders during decontamination. To this solution, NaOH was added with no additional pNP production observed. Thus it was concluded that the solution had no residual MPT present in the bulk solution. Therefore, a 100% conversion was indicated. Next, the particles were collected from solution and washed with either DMF or acetone. Additional pNP was collected indicating that the missing pNP was actually present but adsorbed in the MOF structure. Graphs 54 and 60,
The kinetics of the MPT hydrolysis were then collected. Without the determining enzyme (OPH) incorporated, decontamination by the SD-MOF is complete within about 3 hours, much faster than any known catalytic particles, and hypersorptive for safe disposal. Out of 100 μM MPT, about 20% MPT or pNP was adsorbed to powders. Graph 100,
The SD-MOF of this invention can be reused many times.
The SD-MOF of this invention can be used to support enzymes, such as OPH, to substantially increase its activity. Graph 140,
Gas phase reactivity of the SD-MOF was also observed. Significant quantities of pNP were able to be extracted from SD-MOF powder sample after 24 hour exposure to methyl paraoxon (MPO) in a gas stream with no moisture. The amount of MPT/pNP produced were varied depending on the experimental conditions.
Continuous decontamination of MPT was demonstrated at a flow rate of about 1 mL/h in the SD-MOF powders of packed bed reactor 150 (PBR),
The observed activity from PBR 150,
Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments.
In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended.
Other embodiments will occur to those skilled in the art and are within the following claims.
This application hereby claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/194,769, filed on Sep. 30, 2008 under 35 U.S.C. §§119, 120, 363, 365, and 37 C.F.R. §1.55 and §1.78, which is hereby incorporated herein by reference.
Number | Date | Country | |
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61194769 | Sep 2008 | US |