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.

Developing methods to detect, adsorb, and decompose chemical warfare agents (CWAs) is of critical importance to protecting military and civilian populations alike. The sorption of dimethyl methylphosphonate (DMMP), a CWA simulant, into trisilanolphenyl-POSS (TPP) films has previously been characterized with reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and uptake coefficient determinations [1]. In our study, the quartz crystal microbalance (QCM) is used to study the sorption phenomena of DMMP into highly ordered Langmuir-Blodgett (LB) films of TPP. In a saturated environment, DMMP sorbs into the TPP films, binding to TPP in a 1:1 molar ratio. Although previous work indicated these DMMP-saturated films were stable for several weeks, DMMP is found to slowly desorb from the TPP films at room temperature and pressure. Upon application of vacuum to the DMMP-saturated films, DMMP follows first-order desorption kinetics and readily desorbs from the film, returning the TPP film to its original state. [1] Ferguson-McPherson, M.; Low, E.; Esker, A.; Morris, J. J. Phys. Chem. B. 2005, 109, 18914. / Master of Science

Polymer electrolyte membrane fuel cells (PEMFCs) are one of the most promising clean technologies under development. However, the main obstacles for commercialising PEMFCs are largely attributed to the technical limitations and cost of current PEM materials such as Nafion. Novel poly(2,5-benzimidazole) (ABPBI)/POSS based polymer composite electrolyte membranes with excellent mechanical and conductivity properties were developed in this project including (I) ABPBI, polybenzimidazole (PBI) and their copolymers were synthesised by solution polymerisation and their chemical structures were confirmed by FTIR and elemental analysis. ABPBI/ActaAmmonium POSS (ABPBI/AM) and ABPBI/TriSilanolPhenyl POSS (ABPBI/SO) composites were also synthesised in situ. High quality polymer and composite membranes were fabricated by a direct cast method; and (II) The mechanical and thermal properties, microstructure and morphology, water and H3PO4 absorbility and proton conductivity of phosphoric acid doped and undoped ABPBI and ABPBI/POSS composite membranes were investigated. SEM/TEM micrographs showed that a uniform dispersion of POSS nano particles in ABPBI polymer matrix was achieved. The best performances on both mechanical properties and proton conductivities were obtained from the ABPBI/AM composite membrane with 3 wt% of POSS (ABPBI/3AM). It was found that both the water and H3PO4 uptakes were increased significantly with the addition of POSS due to formation of hydrogen bonds between the POSS and H2O/H3PO4, which played a critical role in the improvement of the conductivity of the composite membranes at temperatures over 100oC. ABPBI/3AM membranes with H3PO4 uptake above 117% showed best proton conductivities at both hydrous and anhydrous conditions from room temperature to 160oC, which is comparable with the conductivity of commercial Nafion 117 at 20oC in water-saturated condition, indicating that these composite membranes could be excellent candidates as a polymer electrolyte membrane for high temperature applications. A new mechanism for illustrating the improved proton conductivity of composite membranes was also developed.