FOCUS AREA(S): General Warfighting Requirements (GWR) TECHNOLOGY AREA(S): Chemical/Bio Defense, Materials/Processes OBJECTIVE: Develop and demonstrate the scaled synthesis of porous organic polymers (POPs) such as polymers of intrinsic microporisity (PIMs) or covalent organic frameworks (COFs) and process them into functional form factors for protection applications. DESCRIPTION: This topic seeks to scale the synthesis and processing of POPs to quantities sufficient for developing and integrating novel polymer-based protection technologies. POPs are a family of functional porous materials made from light elements with intrinsic porosity based on a set of rigid or semi-rigid building blocks. POPs can be amorphous or highly crystalline and are highly effective in adsorption and catalysis applications. PIMs have high capacities towards a variety of toxic chemicals due to their microporous nature and have some advantages over current filtration materials.1 COFs are also highly porous with tunable pore size and shape and have been shown to be highly effective in various filtration applications.2,3 The chemistry of both classes can be tuned to include different chemical functionalities on the pore walls that absorb and react with various chemicals and provide broad spectrum protection.4,5 PIMs and COFs can be processed into various form factors, including fibers, films, and foams, lending them useful in technologies such as novel helmet-integrated filters, textiles, and coatings.6-8 Furthermore, PIMs and COFs can change their refractive index or luminescence upon chemical adsorption, allowing for multifunctional sensing materials.9,10 The primary limitation to further implementation is related to the cost of large-scale synthesis and processing. Many of the monomers required to form PIMs or COFs are expensive, the synthesis conditions require harsh solvents at high temperatures and require complicated purification procedures to access high surface area materials. Similarly, processing into useful form factors also requires harsh solvents and in the case of COFs, in can be difficult to access sufficiently large crystal sizes and alignment. Thus, we seek the development of novel synthesis and processing approaches to access POPs on sufficiently large scales to make functional forms, such as fibers, films, and foam. Multiple PIMs, COFs or other POPs will be synthesized targeting toxic industrial chemical removal (threshold) and sensing (objective). Target chemicals include, but are not limited to, chlorine, nitrogen dioxide, ammonia, and sulfur dioxide. PHASE I: The offeror(s) shall develop an approach to synthesis at least 2 POPs at a scale of 1 kg. Optionally, POPs can be used as functional binders to complement activity of other porous materials such as metal-organic frameworks (MOFs). The materials synthesized will have a minimum porosity of 500 m2/g and be amenable to post-synthetic modification allowing for the integration of appropriate nucleophilic species. The offeror(s) shall perform a preliminary study of the detoxification of a chemical warfare agent simulant and will show substantial uptake (similar to broad spectrum reactive carbons) and reaction towards toxic chemicals of interest. PHASE II: The offeror(s) shall build upon the method developed in Phase I to scale up POP synthesis to 20-100 kg quantities and optimize synthesis routes to minimize cost. Furthermore, cost-effective processing routes will be developed to transform powdered POPs into at least 1 functional form (e.g. granule, bead, fiber, foam) useful for filtration which should be mechanically robust with a modulus of at least 5 GPa and strength of at least 0.5 GPA. Alternatively, the offeror(s) may develop a hybrid approach where the POP is both synthesized and processed in a single step from the constituent building blocks. Development of form factors and prototype filters will be initiated targeting NIOSH CBRN chemicals. PHASE III: The offeror(s) shall build upon methods developed in Phase I and Phase II to develop a fully functional prototype and collaborate with industry partners to develop technologies such as novel filters, textiles/suits, foams, sensors, and more. PHASE III DUAL USE APPLICATIONS: First responder personnel, pesticide applications personnel, industrial/lab waste kits, water filtration, gas storage, etc. would all benefit from a health & safety perspective resulting from the proposed technology. References: 1. Jung, D.; Das, P.; Atilgan, A.; Hupp, J. T.; Islamoglu, T.; Kalow, J.A.; Farha, O. K. Reactive Porous Polymers for Detoxification of a Chemical Warfare Agent Simulant Chem. Mater. 2020, 32 (21), 9299. 2. Tan, K.T., Ghosh, S., Wang, Z. et al. Covalent organic frameworks. Nat Rev Methods Primers 2023, 3,1. 3. Yuan, S.; Li, X.; Zhu, J.; Zhang, G.; Puyvelde, P. V.; Van der Bruggen, B. Covalent Organic Frameworks for Membrane Separation Chem. Soc. Rev. 2019, 48, 2665. 4. Jung, D.; Chen, Z.; Alayoglu, S.; Mian, M. R.; Goetjen, T. A.; Idrees, K. B.; Kirlikovali, K. O.; Islamoglu, T.; Farha, O. K. Postsynthetically Modified Polymers of Intrinsic Microporosity (PIMs) for Capturing Toxic Gases ACS Appl. Mater. Interfaces 2021, 13 (8), 10409. 5. Segura, J. L.; Royuela, S.; Ramos, M. M. Post-synthetic Modification of Covalent Organic Frameworks Chem. Soc. Rev. 2019, 48, 3903. 6. Topuz, F.; Abdellah, M. H.; Budd, P. M.; Abdulhamid, M. A. Advances in Polymers of Intrinsic Microporosity (PIMs)-Based Materials for Membrane, Environmental, Catalysis, Sensing and Energy Applications Polymer Reviews 2024, 64 (1), 251. 7. Snider, V. G.; Hill, C. L. Functionalized reactive polymers for the removal of chemical warfare agents: A review Journal of Hazardous Materials 2023, 442, 130015. 8. Barnes, M. G.; McLeod, D. C.; Lambeth, R. H. Highly Crystalline, Free-Standing Covalent Organic Framework Films Produced Directly from Monomer Solutions ACS Appl. Polym. Mater. 2022, 4, 2017. 9. Rakow, N. A.; Wendland, M. S.; Trend, J. E.; Poirier, R. J.; Paolucci, D. M.; Maki, S. P.; Lyons, C. S.; Swierczek, M. J. Visual Indicator for Trace Organic Volatiles Langmuir 2010, 26 (6), 3767. 10. Liu, X.; Huang, D.; Lai, C.; Zeng, G.; Qin, L.; Wang, H.; Yi, H.; Li, B.; Liu, S.; Zhang, M.; Deng, R.; Fu, Y.; Li, L.; Xue, W.; Chen, S. Recent advances in covalent organic frameworks (COFs) as a smart sensing material Chem. Soc. Rev. 2019, 48, 5266. KEYWORDS: porous organic polymer, covalent organic framework, polymers of intrinsic microporosity, protection, filtration, scaling, engineering, forming
