Nerve Agent Degradation Using Polyoxoniobates

Polyoxoniobates are exceptional amongst polyoxometalates in that they can potentially perform base catalysis in water, a process in which a proton is bonded to an oxo ligand, and a hydroxyl is released. Catalytic decomposition of chemical warfare agents such as organofluorophosphates that were used recently in the infamous civilian attacks in Syria is one opportunity to employ this process. Upon evaluation of the polyoxoniobate Lindqvist ion, [Nb₆O₁₉]⁸⁻ fast neutralization kinetics was discovered for the breakdown of the nerve agent simulant diisopropyl fluorophosphate (DFP). Further testing of the polyoxoniobates against nerve agents Sarin (GB), and Soman (GD) was also performed. It was determined that different Lindqvist countercations (Li, K, or Cs) affect the rate of decomposition of the organophosphate compounds in both aqueous media (homogeneous reaction), and in the solid-state (heterogeneous reaction). Small-angle X-ray scattering of solutions of the Li, K, and Cs [Nb₆O₁₉]⁸⁻ salts at concentrations which the experiments were performed revealed distinct differences that could be linked to their relative reaction rates. This study represents the first demonstration of exploiting the unique alkaline reactivity of polyoxoniobates for nerve agent decontamination.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Wiley-VCH and can be found at: http://onlinelibrary.wiley.com/doi/10.1002/ejic.201400016/full.Keywords: Nerve agents, Small-angle X-ray scattering, Kinetics, Polyoxometalates, Ion pair

Quantum Calculations of VX Ammonolysis and Hydrolysis Pathways via Hydrated Lithium Nitride

Recently, lithium nitride (Li3N) has been proposed as a chemical warfare agent (CWA) neutralization reagent for its ability to produce nucleophilic ammonia molecules and hydroxide ions in aqueous solution. Quantum chemical calculations can provide insight into the Li3N neutralization process that has been studied experimentally. Here, we calculate reaction-free energies associated with the Li3N-based neutralization of the CWA VX using quantum chemical density functional theory and ab initio methods. We find that alkaline hydrolysis is more favorable to either ammonolysis or neutral hydrolysis for initial P-S and P-O bond cleavages. Reaction-free energies of subsequent reactions are calculated to determine the full reaction pathway. Notably, products predicted from favorable reactions have been identified in previous experiments

Enhanced Micellar Catalysis LDRD.

The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesota's Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters

Ultrahydrophobic Textiles Using Nanoparticles: Lotus Approach

It is well established that the water wettability of ma-terials is governed by both the chemical composition and the geometrical microstructure of the surface.1 Traditional textile wet processing treatments do in-deed rely fundamentally upon complete wetting out of a textile structure to achieve satisfactory perform-ance.2 However, the complexities introduced through the heterogeneous nature of the fiber surfaces, the nature of the fiber composition and the actual con-struction of the textile material create difficulties in attempting to predict the exact wettability of a par-ticular textile material. For many applications the ability of a finished fabric to exhibit water repellency (in other words low wettability) is essential2 and po-tential applications of highly water repellent textile materials include rainwear, upholstery, protective clothing, sportswear, and automobile interior fabrics. Recent research indicates that such applications may benefit from a new generation of water repellent ma-terials that make use of the “lotus effect” to provide ultrahydrophobic textile materials.3,4 Ultrahydropho-bic surfaces are typically termed as the surfaces that show a water contact angle greater than 150°C with very low contact angle hysteresis.4 In the case of tex-tile materials, the level of hydrophobicity is often determined by measuring the static water contact angle only, since it is difficult to measure the contact angle hysteresis on a textile fabric because of the high levels of roughness inherent in textile structures