Effects of amphiphilic polymers in solution on the behavior of reverse microemulsions of alkane/water/AOT

Reverse microemulsions are important systems for investigation both for theoretical studies as a model system consisting of nearly mono-disperse spheres, and for many practical industrial applications. The Aerosol-OT/hydrocarbon/water reverse microemulsion system allows for the creation of nano-scale water domains with very high interfacial surface area. These properties have enabled reverse microemulsions to be used in a variety of special applications including micro-reactors for polymerization, adjustable templates to create inorganic nano-particles, and also as a means to increase enzyme activity when placed in reverse microemulsions.; The effect of amphiphilic polymers in solution on the behavior of reverse microemulsions was investigated using a block copolymer of polybutadiene - polyethylene oxide and a comb like polymer of polymaleic anhydride octyl vinyl ether. A di-functional carboxylic acid (six carbon chain adipic acid) was used as a novel additive for the AOT reverse microemulsion system and other simple additives were examined for reference purposes.; The amphiphilic polymers and simple additives were found to be useful tools in controlling the reverse microemulsion phase stability and manipulating drop - drop interactions. PMAOVE and adipic acid were found to decrease the temperature region where stable reverse microemulsions exist and to increase the attractive drop - drop interactions or rate of effective collisions as verified by electrical percolation, dynamic light scattering and static light scattering. Sodium chloride, hexanoic acid and PBd-PEO were found to have the opposite effects. Electron spin resonance was applied to the polymer - reverse microemulsion systems and found to be a useful way to evaluate polymer and organic acidic adsorption onto the water drops. The primary effect measured by ESR was concluded to be a pH effect involving the protonation of the spin labeled probe leading to increased mobility, and detailed information on the film rigidity could not be obtained.; Dynamic light scattering revealed interesting phenomenon when PMAOVE was added to the reverse microemulsion. A dramatic increase in the drop size at low R values occurred that indicated an uncoiling of the polymer by drop attachment. The charge on the reverse microemulsion droplets was determined by electroacoustics and electrophoretic light scattering and found to be insignificant for the simple reverse microemulsion system in the stable nano drop size region.; A model was developed to predict the electrical percolation behavior for small changes in film rigidity based on considerations of the mixed film composition and geometric parameters of the polymer and organic acids used as additives to the reverse microemulsion system. A drop - drop bridging mechanism was also elucidated using structural models of the polymer - reverse microemulsion drops that were consistent with the experimental findings and molecular parameters of the drop and polymers. Thus the role of the polymer structure was related to the microemulsion stability and behavior.