Solvent extraction is one of the methods available for the decontamination of sensitive equipments that are contaminated with chemical warfare agents. The efficiency of extraction method have been verified on the samples, (steel or rubber) that have been contaminated with drops of mustard gas. These samples have been inserted into the extraction flow cell through which solvent (ethoxynonafluorobutane - HFE-7200) flowed. The solvent was sampled in the time intervals. These samples of solvent were analysed for the concentration of mustard gas. Process of extraction was monitored for the three operational factors (the solvent flow rate, temperature and the ultrasound power) and for three different situations (dissolution of drops of mustard gas, mustard gas desorption from the structure of the sample and dissolve drops of mustard gas with the subsequent desorption from the sample). The development of the decontamination process in time was found to consist of two stages. In the first stage the rapid dissolution of the liquid part of mustard gas in a solvent and in the second phase was such as mustard desorption from the structure of the sample and this phase was considerably slower. Extraction is to accelerate increasing the value of the flow of the solvent, the temperature and the performance of the ultrasound. These operational fac-tors have a significant impact on the thickness of the laminar layer of solvent, the solvent replacement coefficient in a cell, diffusion parameters in the process, the viscosity, the solubility of mustard gas in a solvent and the maximum achievable concentration of mustard gas in the rubber sample. The values of adjustable parameters was obtained by mathematical analysis of mathematical model. The progress of extraction under different operational conditions can be predicted by these parameters. The effect of solvents and ultrasound was experimentally verified for selected equipments of computing and communication technology. The possibility of separation of chemical warfare agents from the solvent was verified too.

Developing a fundamental understanding of the interactions of chemical warfare agents (CWAs) with surfaces is essential for the rational design of new sorbents, sensors, and decontamination strategies. The interactions of chemical warfare agent simulants, molecules which retain many of the same chemical or physical properties of the agent without the toxic effects, with amorphous silica were conducted to investigate how small changes in chemical structure affect the overall chemistry. Experiments investigating the surface chemistry of two classes of CWAs, nerve and blister agents, were performed in ultrahigh vacuum to provide a well-characterized system in the absence of background gases. Transmission infrared spectroscopy and temperature-programmed desorption techniques were used to learn about the adsorption mechanism and to measure the activation energy for desorption for each of the simulant studied. In the organophosphate series, the simulants diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), dimethyl chlorophosphate (DMCP), and methyl dichlorophosphate (MDCP) were all observed to interact with the silica surface through the formation of a hydrogen bond between the phosphoryl oxygen of the simulant and an isolated hydroxyl group on the surface. In the limit of zero coverage, and after defect effects were excluded, the activation energies for desorption were measured to be 57.9 ± 1, 54.5 ± 0.3, 52.4 ± 0.6, 48.4 ± 1, and 43.0 ± 0.8 kJ/mol for DIMP. DMMP, TMP, DMCP, and MDCP respectively. The adsorption strength was linearly correlated to the magnitude of the frequency shift of the ν(SiO-H) mode upon simulant adsorption. The interaction strength was also linearly correlated to the calculated negative charge on the phosphoryl oxygen, which is affected by the combined inductive effects of the simulants' different substituents. From the structure-function relationship provided by the simulant studies, the CWA, Sarin is predicted to adsorb to isolated hydroxyl groups of the silica surface via the phosphoryl oxygen with a strength of 53 kJ/mol. The interactions of two common mustard simulants, 2-chloroethyl ethyl sulfide (2-CEES) and methyl salicylate (MeS), with amorphous silica were also studied. 2-CEES was observed to adsorb to form two different types of hydrogen bonds with isolated hydroxyl groups, one via the S moiety and another via the Cl moiety. The desorption energy depends strongly on the simulant coverage, suggesting that each 2-CEES adsorbate forms two hydrogen bonds. MeS interacts with the surface via a single hydrogen bond through either its hydroxyl or carbonyl functionality. While the simulant work has allowed us to make predictions agent-surface interactions, actual experiments with the live agents need to be conducted to fully understand this chemistry. To this end, a new surface science instrument specifically designed for agent-surface experiments has been developed, constructed, and tested. The instrument, located at Edgewood Chemical Biological Center, now makes it possible to make direct comparisons between simulants and agents that will aid in choosing which simulants best model live agent chemistry for a given system. These fundamental studies will also contribute to the development of new agent detection and decontamination strategies. / Ph. D.

Indiana University-Purdue University Indianapolis (IUPUI) / Paper spray is an ambient ionization technique for mass spectrometry that is well-known for its ability to accomplish rapid and sensitive analyses without any need for sample preparation. This work further develops the technique in two major areas: negative ionization and drug screening. Negative ionization has always been an obstacle to electrospray-based ion sources because of its vulnerability to corona discharge, but methods are presented here to both quantify and suppress this electrical phenomenon, thus preventing it from interfering with qualitative/quantitative analyses. The validity of the discharge-suppressing method is demonstrated for both a simple screen of barbiturates and other acidic drugs (Chapter 2) and the detection and quantitation of chemical warfare agent hydrolysis products (Chapter 3). Additionally, a positive ion drug screen is applied to the analysis of postmortem blood samples (Chapter 4), achieving rapid and effective screening of 137 different drugs ranging from pharmaceuticals to drugs of abuse. The performance of this screen is also evaluated by comparing the results of the postmortem samples to those obtained using a more established series of assays. The research contained herein presents strides toward forensic application of paper spray mass spectrometry, especially in disciplines related to forensic toxicology.

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The reactivity of chemical warfare agents (CWAs) and CWA simulants on organic and oxide surfaces is not currently well understood, but is of substantial importance to the development of effective sensors, filters and sorbent materials. Polyurethane coatings are used by the armed forces as chemical agent resistive paints to limit the uptake of CWAs on surfaces, while the use of metal oxides has been explored for decontamination and protection purposes. To better understand the chemical nature of the interactions of organophosphonate simulants with these surfaces, an ultra-high vacuum environment was used to isolate the target interactions from environmental gaseous interferences. The use of highly-characterized surfaces, coupled with molecular beam and dosing capabilities, allows for the elucidation of adsorption, desorption, and reaction mechanisms of CWA simulants on a variety of materials. Model urethane-containing organic coatings were designed and applied toward the creation of well-ordered thin films containing carbamate linkages. In addition, novel trisilanolphenyl-polyhedral oligomeric silsesquioxane (POSS) molecules were used to create Langmuir-Blodgett films containing reactive silanol groups that have potential use as sensors and coatings. The uptake and reactivity of organophosphonates and chlorophosphates on these surfaces is the focus of this study. Surfaces were characterized before and after exposure to the phosphates using a number of surface sensitive techniques including: contact angle goniometry, reflection-absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD) measurements. In conjunction with surface probes, uptake coefficients were monitored according to the King and Wells direct reflection technique. The integration of these analytical techniques provides insight and direction towards the design of more effective chemical agent resistant coatings and aids in the development of more functional strategies for chemical warfare agent decontamination and sensing. / Ph. D.

Reflection absorption infrared spectroscopy was used as the primary analysis technique to study the interfacial chemistry of surfaces relevant to chemical and biological warfare agent defense. Many strategies utilized by the military to detect and decompose chemical and biological warfare agents involve their interaction with surfaces. However, much of the chemistry that occurs at the interface between the agents and surfaces of interest remains unknown. The surface chemistry plays an important role in efficacy of both detection and decontamination technology, and by obtaining a deeper understanding of that chemistry, researchers might be able to develop more sensitive detection devices and more effective decontamination strategies. Our efforts have focused on three different areas of surface chemistry relevant to chemical and biological warfare agent defense: 1) The development of a surface synthesis strategy to create and control the structure of antibacterial self-assembled monolayers (SAMs). Our work demonstrated a successful strategy for creating SAMs that contain long-chain quaternary ammonium groups, which were synthesized and subsequently characterized using RAIRS and X-ray photoelectron spectroscopy (XPS). 2) The determination of the surface conformation, orientation, and relative surface density of immobilized antimicrobial peptides. Our results revealed that the peptides consisted of tilted (50-60°), α-helices on the surface, regardless of solution conditions. 3) The design and construction of a new ultrahigh vacuum surface science instrument that allows for the study of gas-surface reactions with up to three gases simultaneously. 4) The study of the adsorption of chemical warfare agent simulants to silica nanoparticulate films. Our work demonstrated that the adsorbate structure was dependent on the number of hydrogen-bonding groups, and the adsorption consists of a pressure-dependent two part mechanism. The results presented here will help increase the understanding of the surface chemistry of three interfaces relevant to chemical and biological defense. Future researchers may apply the new information to develop more effective detection and decontamination strategies for chemical and biological warfare agents. / Ph. D.

The targeted design of new catalyst materials can only be accomplished once a fundamental understanding of the interactions between material surfaces and adsorbed molecules is developed. In situ infrared spectroscopy and mass spectrometry methods were employed to probe interactions at the gas-surface interface of oxide-supported metal nanoparticle materials. High vacuum conditions allowed for systematic investigations to describe detailed reaction mechanisms. Specifically, variable temperature infrared spectroscopy was utilized to uncover the binding energetics of CO to the oxide surface of TiO2-based materials. As binding energetics are related to the electronic structure of the adsorption site, differences in evaluated binding enthalpies are hypothesized to probe electronic metal-support interactions that describe charge transfer between the supported metal nanoparticles and TiO2. Cu/TiO2 aerogels were identified as a candidate for more in-depth studies. Flow reactor methods in combination with the surface-based infrared spectroscopy were utilized to elucidate the CO oxidation reaction mechanism over Cu/TiO2 aerogels. Bridging oxygen atoms on TiO2 regions of the material were identified as the active site for catalysis in a Cu-assisted Mars-van Krevelen lattice extraction mechanism. Methanol oxidation was then studied with similar methods to show the complete conversion to CO2 and H2O at high temperatures through the reduction of titania and formation of a formate intermediate. Higher-order carbonaceous alcohols were probed for adsorption and reactivity on Cu/TiO2 aerogels and were observed to follow a similar reaction pathway. The higher-order alcohols, however, were shown to undergo a partial oxidation pathway in the absence of gaseous O2 that is hypothesized to originate from enhanced binding to Cu sites. The decomposition of the chemical warfare agent simulant dimethyl chlorophosphate was also investigated. A hydrolysis pathway to form the significantly less toxic molecule CH3Cl was observed, highlighting the unique promotional effects and chemistry on Cu/TiO2 aerogels. The results presented exemplify both the influence of electronic metal-support interactions on catalysis and the versatile reactivity of Cu/TiO2 aerogels. / Doctor of Philosophy / Interactions between small gaseous molecules and material surfaces have very important implications for applications regarding the environment, industry, and military/public safety. The mechanisms in which gases interact with a solid surface can determine how the material can be functionally used as catalysts. Scientists and engineers start to build a fundamental understanding of what makes a catalyst successful for different applications by understanding the location and strength of interactions. A catalyst's surface acts to lower activation barriers and provide low-energy pathways for interacting molecules to chemically change, by breaking bonds for molecular decomposition and/or forming new bonds. The vibrations of chemical bonds that break and form on surfaces are probed with infrared spectroscopy at the gas-surface interface to study molecular adsorption and reactivity. In addition, a flow cell reactor is used to characterize reaction progress and identify products in real-time. A class of reactive nanoparticulate materials is utilized as a model system on which to study various chemical reactions for important applications including small molecule oxidation for industrial detoxification and clean energy applications, as well as the decomposition of chemical warfare agents. Reaction mechanisms for the oxidation of carbon monoxide and alcohols were elucidated through the utilization of the methods described above. In addition, the decomposition of a chemical warfare agent simulant is characterized. The discoveries and understanding of important chemical properties presented in this dissertation will aid in the synthesis of effective next-generation catalyst materials.