| olyaniline has recently been found to be a highly selective membrane for gas separations. Understanding the polymer properties or factors that influence permeability will lead to improvements in separations and tailoring for specific gas pairs. An introduction to polyaniline's synthesis, characterization and film formation is presented followed by a brief overview of gas separation fundamentals.;Polyaniline can be reversibly doped and undoped using common acids and bases. This process allows one to tailor the membrane's properties after film formation and it is explored in chapter two. Variable acid concentration can be used to control the percent doping in the polyaniliae films. Through element analysis, a quantitative relationship between the pH of the doping acid solution and the percent doping of the membrane was developed. Conductivity measurements show that conductivity increases as percent doping increases, whereas gas permeability of oxygen and nitrogen through the membranes decreases as percent doping increases.;In Chapter Three, a fundamental study of proton diffusion was initiated in order to further understand polyaniline's transport properties. For as-cast polyaniliae membranes, a diffusion coefficient (D) on the order of 1 ;Polyaniline is limited by poor thermal processability and solvent solubility. The introduction of bulky side groups to the polymer backbone is discussed in chapter four as a means to improving the solubility of the polymer. Solvent solubility is increased for ethyl and methoxy substituted polyanilines, and an ethyl copolymer of polyaniline. The smooth free-standing membranes cast from these substituted polymers exhibit an increase in gas permeability compared to the base form of polyaniline, but a decrease in selectivity.;Carbon 60 (C;In the last chapter, the encapsulation of rare-earth metals in carbon cages has been carried out by vaporizing composite rods of the metal oxide... |
