Metal–organic framework (MOF) fibrous composites were synthesized in a variety of methods in attempt to incorporate the highly effective reactivity of MOFs into a more facile and applicable format. Recent advances have demonstrated incorporating a metal oxide nucleation surface or reactive layer promotes conformal, well-adhered MOF growth on substrates. These materials have demonstrated promising reactivity in capturing or degrading chemical warfare agents and simulants. Here, we examine the mechanisms for MOF nucleation from metal oxide thin films to explore why some metal oxide sources are better suited for one synthesis mechanism over another. We isolate metal oxide extent of hydroxylation as an indicative factor as to whether the film serves as a nucleation promoter or may be converted directly to the MOF thin films. MOF-525 growth on Al2O3, TiO2, and ZnO coated fibers is demonstrated to corroborate these findings and used to degrade chemical warfare agent simulant dimethyl-4-nitrophenyl phosphate.

New materials and chemical knowledge for improved personal protection are among the mostp ressing needs in the international community.R eported attacks using chemical warfare agents(CWAs,) including organophosphate soman (GD) and thioether mustard gas (HD) are driving research in field-deployable catalytic composites for rapid toxin degradation. In this work, we reports imple template-free low temperature synthesis that enables for the first time, ad eployable-structured catalytic metal-organic framework/polymer textile composite "MOF-fabric" showing rapid hydrolysis and oxidationo fm ultiple active chemical warfare agents, GD and HD, respectively,a nd their simulants. Our method yields new zirconium-porphyrin based nanocrystalline PCN-222 MOF-fabrics with adjustable MOF loading and robustm echanical adhesion on low-cost nonwoven polypropylene fibers. Importantly,w ed escribe quantitative kinetic analysisc onfirming that our MOF-fabrics are as effective as or better than analogousM OF powders for agent degradation, especially for oxidation. Faster oxidation using the MOF-fabrics is ascribed to the composite geometry, where active MOF catalysts are uniformly displayed on the MOF-textile enabling better reactant transport and reactive oxidantg eneration.F urthermore, we notet he discovery of visible photo-activation of GD hydrolysis by aM OF-fabric, which is ascribed to oxidation at the active metal node site, significantly increasing the rate over that observed without illumination. These results provide importantn ew insights into the design of future materials and chemical systems to protectm ilitary,f irst-responders, and civilians upon exposure to complex chemical toxins.

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven effective in gas adsorption, separations, and catalysis. MOFs are most commonly synthesized as bulk powder, requiring additional processes to adhere them to functional devices and fabrics that risk decreasing the powder porosity and adsorption capacity. Here, we demonstrate a method of first coating fabrics with metal oxide films using atomic layer deposition (ALD). This process creates conformal films of controllable thickness on each fiber, while providing a more reactive surface for MOF nucleation. By submerging the ALD coated fabric in solution during solvothermal MOF synthesis, the MOFs create a conformal, well-adhered coating on the fibers, resulting in a MOF-functionalized fabric, without additional adhesion materials that may block MOF pores and functional sites. Here we demonstrate two solvothermal synthesis methods. First, we form a MIL-96(Al) layer on polypropylene fibers using synthetic conditions that convert the metal oxide to MOF. Using initial inorganic films of varying thicknesses, diffusion of the organic linker into the inorganic allows us to control the extent of MOF loading on the fabric. Second, we perform a solvothermal synthesis of UiO-66-NH2 in which the MOF nucleates on the conformal metal oxide coating on polyamide-6 (PA-6) fibers, thereby producing a uniform and conformal thin film of MOF on the fabric. The resulting materials can be directly incorporated into filter devices or protective clothing and eliminate the maladroit qualities of loose powder.

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