Atomic layer deposition/
Metal-organic frameworks

Highly Breathable Chemically Protective MOF‐Fiber CatalystsAdvanced Functional Materials, part of the prestigious Advanced portfolio and a top-tier materials science journal, publishes outstanding research across the field.

Protective Fabrics: Metal-Organic Framework Textiles for Rapid Photocatalytic Sulfur Mustard Simulant DetoxificationMetal-organic frameworks (MOFs) can catalyze toxic chemical decontamination, but new MOF materials and synthesis strategies are needed to improve perf…

Toxic Organophosphate Hydrolysis Using Nanofiber-Templated UiO-66-NH2 Metal–Organic Framework Polycrystalline CylindersMetal organic frameworks (MOFs), the UiO series in particular, have attracted much attention because of the high surface area and ability to capture and decontaminate chemical warfare agents. Much work has been done on incorporating these MOFs into or onto textile materials while retaining the desirable properties of the MOF. Many different techniques have been explored to achieve this. Atomic layer deposition (ALD) of TiO2 followed by solvothermal synthesis of MOF has become one of the most adaptable techniques for growing MOFs on the surface of many different polymer fabric materials. However, little work has been done with using this technique on polymer composite materials. In this work, UiO-66-NH2 was grown onto the surface of poly(methyl methacrylate) (PMMA)/Ti(OH)4 and poly(vinylidene fluoride) (PVDF)/Ti(OH)4 composite fibers by first modifying the surface with ALD of TiO2 (@TiO2) followed by solvothermal synthesis of MOF (@MOF). The catalytic activity of these materials was then evaluated using the simulant paraoxon-methyl (DMNP). These new MOF-functionalized composite fabrics were compared to polyamide-6 (PA-6)@TiO2@MOF- and polypropylene (PP)@TiO2@MOF-functionalized fabrics. PMMA/Ti(OH)4@TiO2@MOF fibers resulted in unique hollowed fibers with high surface area of 264 m2/g and fast catalytic activity. The catalytic activity of these samples was found to be related to the active MOF mass fraction on the MOF-functionalized composite fabric, with the hollowed PMMA/Ti(OH)4@TiO2@MOF having the highest weight percent of active MOF and a DMNP t1/2 of 26 min followed by PA-6@TiO2@MOF with 45 min, PVDF/Ti(OH)4@TiO2@MOF with 61 min, and PP@TiO2@MOF with 83 min.

Water‐Stable Chemical‐Protective Textiles via Euhedral Surface‐Oriented 2D Cu–TCPP Metal‐Organic FrameworksChemical protective metal-organic framework (MOF)/fiber composites highly adsorptive for NH3 and 2-chloroethyl ethyl sulfide (CEES), a vesicant sulfur mustard simulant, are fabricated. The facile syn...

Catalytic “MOF-Cloth” Formed via Directed Supramolecular Assembly of UiO-66-NH2 Crystals on Atomic Layer Deposition-Coated Textiles for Rapid Degradation of Chemical Warfare Agent SimulantsHighly tunable metal–organic framework (MOF) materials, including, for example, UiO-66-NH2, are known to be effective catalysts to degrade chemical warfare agents (CWAs) with half-lives near 1 min. Therefore, many researchers have been actively working on producing supported MOF materials to improve application effectiveness by using relatively slow solvothermal synthesis or repetitious stepwise layer-by-layer methods. Herein, we demonstrate a facile route to rapidly assemble presynthesized UiO-66-NH2 crystals onto nonwoven polypropylene (PP) fibrous mats at ambient temperature. Crystal assembly is chemically directed using β-cyclodextrin (β-CD) and cetyltrimethylammonium bromide (CTAB) as surfactant assembly agents, where the agents quickly (within 5 min) self-assemble on the crystal surface and promote physically robust chemical surface attachment while simultaneously impeding solution-phase crystal agglomeration. Furthermore, we find that when the PP is preconditioned using conformal metal oxide thin films, including Al2O3, TiO2, or ZnO formed via atomic layer deposition (ALD), the hydrophilic metal oxide surface further helps improve assembly uniformity and MOF mass loading, producing MOF crystal loading as high as 40 wt % and an overall BET surface area exceeding 200 m2/g(MOF+Fiber). Using these surface-assembled MOFs, we observe catalytic degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a CWA simulant, with a half-life of less than 5 min.

UiO-66-NH2 Metal–Organic Framework (MOF) Nucleation on TiO2, ZnO, and Al2O3 Atomic Layer Deposition-Treated Polymer Fibers: Role of Metal Oxide on MOF Growth and Catalytic Hydrolysis of Chemical Warfare Agent SimulantsMetal–organic frameworks (MOFs) chemically bound to polymeric microfibrous textiles show promising performance for many future applications. In particular, Zr-based UiO-66-family MOF-textiles have been shown to catalytically degrade highly toxic chemical warfare agents (CWAs), where favorable MOF/polymer bonding and adhesion are attained by placing a nanoscale metal-oxide layer on the polymer fiber preceding MOF growth. To date, however, the nucleation mechanism of Zr-based MOFs on different metal oxides and how product performance is affected are not well understood. Herein, we provide new insight into how different inorganic nucleation films (i.e., Al2O3, ZnO, or TiO2) conformally coated on polypropylene (PP) nonwoven textiles via atomic layer deposition (ALD) influence the quality, overall surface area, and the fractional yield of UiO-66-NH2 MOF crystals solvothermally grown on fiber substrates. Of the materials explored, we find that TiO2 ALD layers lead to the most effective overall MOF/fiber adhesion, uniformity, and a rapid catalytic degradation rate for a CWA simulant, dimethyl p-nitrophenyl phosphate (DMNP) with t1/2 = 15 min, 580-fold faster than the catalytic performance of untreated PP textiles. Interestingly, compared to ALD TiO2 and Al2O3, ALD ZnO induces a larger MOF yield in solution and mass loading on PP fibrous mats. However, this larger MOF yield is ascribed to chemical instability of the ZnO layer under MOF formation condition, leading to Zn2+ ions that promote further homogeneous MOF growth. Insights presented here improve understanding of compatibility between active MOF materials and substrate surfaces, which we believe will help advanced MOF composite materials for a variety of useful functions.

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