Metal-organic frameworks (MOFs) are a new and growing area of materials with high porosity and customizability. UiO-66, a zirconium-based MOF, has shown much interest to the military because of the ability of the MOF to catalytically decontaminate chemical warfare agents (CWAs). Unfortunately, the applications for MOFs are limited because of their powder form, which is difficult to incorporate into protective clothing. As a result, a new area of research has developed to functionalize fabrics with MOFs to make a wearable multifunctional fabric that retains the desired properties of the MOF. In this work, UiO-66 was incorporated into poly(vinylidene) fluoride/Ti(OH) composite fabric using electrospinning and evaluated for its use in chemical protective clothing. The base triethanolamine (TEA) was added to the composite fabric to create a self-buffering system that would allow for catalytic decontamination of CWAs without the need for a buffer solution. The fabrics were tested against the simulants methyl-paraoxon (dimethyl (4-nitrophenyl) phosphate, DMNP), diisopropyl fluorophosphate (DFP), and the nerve agent soman (GD). The results show that all of the samples have high moisture vapor transport and filtration efficiency, which are desirable for protective clothing. The incorporation of TEA decreased air permeation of the fabric, but increased the catalytic activity of the composite fabric against DMNP and DFP. Samples with and without TEA have rapid half-lives ( t) as short as 35 min against GD agent. These new catalytically active self-buffering multifunctional fabrics have great potential for application in chemical protective clothings.

Fibrous composite materials provide distinct advantages in large surface area and enhanced molecular transport through the media, lending themselves to diverse applications. Despite substantial development in synthetic methods, it is still lacking in insights into structure-property relationships that can correlate features of the functional materials to absorptive, transport, and catalytic performance of the composites. Herein, for the first time, a systematic structure-property-function analysis is provided for Zr-based metalorganic frameworks (MOFs) coated onto polypropylene nonwoven textiles. MOF fraction on the fabric and defect density in MOF microstructures are controlled by an in situ seeded growth, where fiber surfaces are pretreated with metal-oxide by atomic layer deposition. The best performing MOF-fiber composite shows a rapid catalytic hydrolysis rate for a chemical warfare agent simulant, p-nitrophenyl phosphate with t 1/2 < 5 min, and a significant permeation restriction of a real agent GD-vapor through the composite. Of added advantage is the observed moisture vapor transport rate of 15 000 g m −2 day −1 for the composite, which is notably superior to that of other commercially available chemical-protective fabrics. The chemical-protective composites realized in this work overcome the breathability/detoxification trade-off and show promise for the materials to be deployed in a realistic field.

Anion exchange membrane fuel cells (AEMFCs) are regarded as a new generation of fuel cell technology that has the potential to overcome many obstacles of the mainstream proton exchange membrane fuel cells (PEMFCs) in cost, catalyst stability, efficiency, and system size. However, the low ionic conductivity and poor thermal stability of current anion exchange membranes (AEMs) have been the key factors limiting the performance of AEMFCs. In this study, an AEM made of styrenic diblock copolymer with a quaternary ammonium-functionalized hydrophilic block and a cross-linkable hydrophobic block and possessing bicontinuous phases of a hydrophobic network and hydrophilic conduction paths was found to have high ionic conductivity at 98 mS cm −1 and controlled membrane swelling with water uptake at 117 wt % at 22 °C. Membrane characterizations and fuel cell tests of the new AEM were carried out together with a commercial AEM, Tokuyama A201, for comparison. The high ionic conductivity and water permeability of the new membrane reported in this study is attributed to the reduced torturosity of the ionic conduction paths, while the hydrophobic network maintains the membrane mechanical integrity, preventing excessive water uptake.

The objective of this work was to fabricate palladium membranes with a Pd/Cu alloy top layer and to investigate the performance and long-term stability of the membranes in small concentrations of H2S. The Pd/Cu alloy membranes with compositions of 8, 18, and 19 wt % copper were fabricated using the electroless deposition method on porous Inconel supports and characterized for several thousand hours in H2, helium, and 45−55 ppm H2S/H2 mixtures in the temperature range of 350−500 °C. Upon exposure to the H2S/H2 mixture at 500 °C, the Pd/Cu membranes lost ∼80% of the hydrogen permeance, because of the H2S forming surface sulfides and blocking H2 adsorption sites, with the amount of permeance lost increasing with decreasing temperature. Reintroducing pure H2 recovered some of the hydrogen permeance, showing that some of the H2S poisoning was irreversible. The amount of irreversible poisoning increased as the H2S exposure time increased and the exposure temperature decreased, because of the exothermic nature of H2S adsorption. The helium leak rate of the Pd/Cu membranes decreased after the poisoning experiments, possibly because of sulfur that segregated to the grain boundaries of the Pd/Cu deposits.

Poly­(N-bromomaleimide) (PMAi-Br), poly­(N-vinylpyrrolidone)-bromine adducts (PVP–Br), and poly­(ethylene-alt-N-bromomaleimide) (PEMAi-Br) and their cross-linked networks are introduced as reactive, self-decontaminating components of protective barriers. Synthetic routes toward polymaleimides include free-radical copolymerization of maleimide with divinyl cross-linkers as well as amidation of poly­(ethylene-alt-maleic anhydride) with urea. The polymers are brominated by bromine in carbon tetrachloride or by copper­(II) bromide in dimethylformamide, with the active bromine contents up to and above 4 mequiv/g, or >30 wt %. The brominated polymer networks exhibit considerable swelling in water and possess reversible redox peak potentials in cyclic voltammetry experiments due to the redox reactions of the bromine present in the polymer structures. In acidic aqueous media, PVP–Br, PMAi-co-DVB-Br, and PEMAi-Br materials are able to degrade 100% of hydrazine, monomethylhydrazine, and 1,1-dimethylhydrazine down to concentrations below detectable levels of 0.15–0.25 mM. The hydrazine is converted to nitrogen gas. The insecticide malathion, tested as a simulant of a combat warfare agent VX, is efficiently and selectively oxidized to malaoxon in the presence of the brominated networks, whereas 2-(chloroethyl)­ethyl sulfide (CEES), a simulant of the sulfur mustard agent, is rapidly oxidized, in both vapor and liquid states, into its less-toxic sulfone derivative, 1-chloro-2-(ethylsulfinyl)­ethane (CEESO), with the only side product being 1,2-bis­(ethylthio)­ethane. The oxidation of CEES is proven to be selective, in that no toxic overoxidized CEES analogue, 1-chloro-2-(ethylsulfonyl)­ethane, is formed. The developed brominated polymer networks are versatile materials with potential applications in coatings, filters, fabrics, and sorbents.