Breathable chemical and biological detoxifying protective fabrics are obtained via functionalization of electrospun fiber mats using a layer-by-layer electrostatic assembly technique. The chemically reactive polyanion, poly(N-hydroxyacrylamide) or poly(hydroxamic acid) (PHA), and bactericidal polycation, poly(N-vinylguanidine) (PVG), were synthesized and assembled electrostatically to generate multifunctional coatings on prefabricated polyacrylonitrile (PAN) fiber mats. Reactivity of PHA in the hydrolysis of diisopropyl fluorophosphate (DFP), a close analog of the chemical warfare agent sarin, was demonstrated. The DFP degradation rate with PHA is comparable to that with compounds such as isonicotinhydroxamic acid methiodide, an efficient catalyst of organophosphate ester hydrolysis. Protective fabrics functionalized with PVG/PHA layers are able to degrade DFP mists, with DFP hydrolysis rates 60-fold higher than those with unmodified fabrics under identical conditions. Fabrics modified with PVG/PHA layers are bactericidal against E. coli and S. epidermidis. Breathability of functionalized fiber mats as protective fabrics was evaluated versus standard reference fabrics.

Polyacrylonitrile (PAN) submicron fiber mats were modified to become reactive components of self-detoxifying chemical protection fabrics. Oximation of the mats with excess hydroxylamine resulted in functionalization of the fibers to form polyacrylamidoxime (PAAO). The fiber morphology remains intact after oximation, with fiber diameters ranging from 250 to 500 nm. Nucleophilic amidoxime groups enable the fiber mats to react with organophosphate pesticides or chemical warfare agents (CWA), as demonstrated using diisopropyl fluorophosphate (DFP) as a CWA simulant. The DFP decomposition kinetics were investigated using 31P MAS NMR, which afforded measurement of the observed pseudo-first order reaction rate constant, kobs. The values of kobs with PAAO-functionalized fibers exceed those of the parent PAN fibers by as much as 80-fold at a water content of 130% by weight. The observed reaction rates depend on the amount of the reactive fiber mats, yielding an apparent second-order rate constant, k2 = 1.0 × 10−6 s−1mg−1. The hydrolytic degradation of DFP occurs only in the presence of free water, which serves as a medium to promote the nucleophilic action of the amidoxime groups in the fibers by facilitating proton transfer and stabilizing the transition state.

: The U.S. Army Natick Soldier Center has been developing methods to incorporate reactive compounds into chemical protective fabrics to decontaminate G-type agents, VX, and mustard (HD). These reactive compounds include: polyoxometalates, magnesium oxide and modified cyclodextrins. Polyoxometalates (POMs), prepared at Emory University, have been incorporated into activated carbon for use in carbon based fabrics and have also been combined with metal oxide powders and reacted with half mustard, CEES. Catalytic activity of the POM/Carbon, POM/MgO, POM/Al2O3, and POM alone in solution were compared to activities in organic fibers and films. Substituted cyclodextrins that were reported in 1992 to be scavengers and catalysts for the hydrolytic cleavage of the P-F bond in soman were used in this study.

: Military, firefighter, law enforcement, and medical personnel require high-level protection when dealing with chemical and biological threats in many environments ranging from combat to urban, agricultural, and industrial. Current protective clothing is based on full barrier protection, such as hazardous materials (HAZMAT) suits, or permeable adsorptive protective overgarments, such as those used by the U.S. military. New protective garment systems are envisioned that contain novel features, such as the capability to selectively block toxic chemicals, to chemically destroy toxic materials that contact the fabric, and to detect hazardous agents on the surface of the fabric. New technologies being built into advanced fabrics for enhanced chemical and biological protection include selectively permeable membranes, reactive nanoparticles, reactive nanofibers, biocidal fabric treatments, and conductive-polymer indicators on optical fibers.

Military, firefighter, law enforcement, and medical personnel require high-level protection when dealing with chemical and biological threats in many environments ranging from combat to urban, agricultural, and industrial. Current protective clothing is based on full barrier protection, such as hazardous materials (HAZMAT) suits, or permeable adsorptive protective overgarments, such as those used by the U.S. military. New protective garment systems are envisioned that contain novel features, such as the capability to selectively block toxic chemicals, to chemically destroy toxic materials that contact the fabric, and to detect hazardous agents on the surface of the fabric. New technologies being built into advanced fabrics for enhanced chemical and biological protection include selectively permeable membranes, reactive nanoparticles, reactive nanofibers, biocidal fabric treatments, and conductive-polymer indicators on optical fibers.

Systematic studies were conducted to observe the binding interactions between the class of compounds including nitroaromatic munitions pollutants trinitrotoluene (TNT) and certain of its breakdown products and dissolved Aldrich humic acid (HA), which is used as a model soil matrix. Equilibrium dialysis followed by HPLC quantitation was used to determine the effect of ligand concentration, HA concentration, pH, and ionic strength on the formation kinetics and ligand binding level of the ligand-HA complex. It was found that TNT and its byproducts 2,6-diamino-4-nitrotoluene (2,6DAmNT) and 2-amino-4,6-dinitrotoluene (2AmDNT) are all able to bind to HA at different binding levels in a slow kinetic process. The HA concentration was observed to have the same inverse effect on the binding of bath TNT and 2,6DAmNT, while pH had opposite effects on binding for the two compounds. Nearly a 2-fold increase in binding of TNT to HA was observed for a 5-fold increase in ionic strength of phosphate buffer. A linear binding model represented the best fit for the 2,6DAmNT isotherm data while the Langmuir model best fit the TNT isotherms. The maximum binding density of TNT for HA calculated from the Langmuir model ranged from 6 to 30 mu M TNT/mu M HA of average size 5000 for all conditions studied. These facts suggest that the binding mechanisms are different for the above two ligands due to their different chemical structures.