MOF Sponges for Enhanced Soldier Lethality

RT&L FOCUS AREA(S): General Warfighting Requirements (GWR) TECHNOLOGY AREA(S): Chem Bio Defense OBJECTIVE: The Army seeks innovative solutions for engineering metal-organic frameworks into composite sponges and foams for use in personal protective equipment (PPE). DESCRIPTION: This topic seeks to develop MOF-polymer composites in the form of sponges and foams for enhanced personal protection equipment (PPE). MOFs offer enhanced protection against chemical warfare agents (CWAs)1-3 and toxic industrial chemicals (TICs)4-6. Sponges and foams can be useful for small footprint filters when used with a mask, ballistic protection if integrated into a helmet, and/or small scale portable decontamination of contaminated areas. In For each of these areas, a combined MOF-sponge composite can lead to enhancements in comparison to currently fielded equipment for improved Soldier Lethality. MOF sponges (and/or foams) will be developed using available techniques that incorporate high mass loadings of MOF (threshold of 50 wt%, objective above 80 wt%). A variety of techniques can be used to make composites resulting in structures such as high internal phase emulsions (polyHIPE) and aerogels.7-9 Composites may be fabricated from pre-existing sponges/foams, with in situ growth of the MOF onto the polymer, or by making the sponge/foam with pre-synthesized MOF. The resulting composite sponges/foams should be mechanically robust, with MOFs adhered to the surface without shedding and the overall structure free-standing. The foams will be compressible and not fully rigid. Composites should withstand/hold up against most common solvents without dissolving. MOFs will be accessible within the sponge/foam composites as assessed by nitrogen porosimetry and chemical activity. Composites will be evaluated for toxic vapor uptake and reactivity, including vapor threats (e.g., ammonia, chlorine, DMMP) and chemical warfare agents/simulants (e.g., DMNP, DFP, GB, GD, HD). PHASE I: Demonstrate the ability to make sponges/foams with multiple MOFs, including HKUST-1, UiO-66-NH2, and MOF-808, at loadings exceeding 50 wt%. MOFs will be accessible to toxic chemicals. Demonstrate the ability to control loading of MOF. The composite will be free-standing and compressible without shedding MOF particles. Composites will be fabricated and delivered to CBC in approximately 3 x 3 x 1 swatches. PHASE II: Optimize composite sponge/foam with respect to mechanical and chemical properties. Understand additional potential benefits of technology, including ballistic/shock protection. Understand the effects of environmental conditions and contaminants on the composite. Scale the process to make commercial-type sponges. Tune processing techniques to understand trade-offs associated with flexibility, hardness, MOF content, MOF shedding, chemical performance, etc. Collect data on composite activity (toxic gas adsorption, breakthrough, permeation, and/or reactivity). PHASE III DUAL USE APPLICATIONS: Collaborate with industry partners to develop technologies, to include novel filter designs, decontamination sponges/wipes, air storage devices, and more. REFERENCES: Son, F.; Wasson, M. C.; Islamoglu, T.; Chen, Z. J.; Gong, X. Y.; Hanna, S. L.; Lyu, J. F.; Wang, X. J.; Idrees, K. B.; Mahle, J. J.; Peterson, G. W.; Farha, O. K., Uncovering the Role of Metal-Organic Framework Topology on the Capture and Reactivity of Chemical Warfare Agents. Chemistry of Materials 2020, 32 (11), 4609-4617. Peterson, G. W.; Moon, S. Y.; Wagner, G. W.; Hall, M. G.; DeCoste, J. B.; Hupp, J. T.; Farha, O. K., Tailoring the Pore Size and Functionality of UiO-Type Metal-Organic Frameworks for Optimal Nerve Agent Destruction. Inorganic Chemistry 2015, 54 (20), 9684-9686. Moon, S. Y.; Proussaloglou, E.; Peterson, G. W.; DeCoste, J. B.; Hall, M. G.; Howarth, A. J.; Hupp, J. T.; Farha, O. K., Detoxification of Chemical Warfare Agents Using a Zr-6-Based Metal-Organic Framework/Polymer Mixture. Chemistry-a European Journal 2016, 22 (42), 14864-14868. DeCoste, J. B.; Browe, M. A.; Wagner, G. W.; Rossin, J. A.; Peterson, G. W., Removal of chlorine gas by an amine functionalized metal-organic framework via electrophilic aromatic substitution. Chemical Communications 2015, 51 (62), 12474-12477. Peterson, G. W.; Mahle, J. J.; DeCoste, J. B.; Gordon, W. O.; Rossin, J. A., Extraordinary NO2 Removal by the Metal-Organic Framework UiO-66-NH2. Angew Chem Int Edit 2016, 55 (21), 6235-6238. Peterson, G. W.; Wagner, G. W.; Balboa, A.; Mahle, J.; Sewell, T.; Karwacki, C. J., Ammonia Vapor Removal by Cu(3)(BTC)(2) and Its Characterization by MAS NMR. Journal of Physical Chemistry C 2009, 113 (31), 13906-13917. Jin, P.; Tan, W. L.; Huo, J.; Liu, T. T.; Liang, Y.; Wang, S. Y.; Bradshaw, D., Hierarchically porous MOF/polymer composites via interfacial nanoassembly and emulsion polymerization. Journal of Materials Chemistry A 2018, 6 (41), 20473-20479. Mazaj, M.; Logar, N. Z.; Zagar, E.; Kovacic, S., A facile strategy towards a highly accessible and hydrostable MOF-phase within hybrid polyHIPEs through in situ lmetal-oxide recrystallization. Journal of Materials Chemistry A 2017, 5 (5), 1967-1971. KEYWORDS: Chemical warfare agent, toxic industrial chemical, filtration, protection, metal-organic framework, MOF, foam, sponge, decontamination