Ultrafine functional fibrous membranes of PSMA-advantages and comparison to PS

This dissertation explores strategies for making fibrous materials with enhanced hydrophilicity and investigated various reactions onto these materials to create a network structure. Fibrous materials are intrinsically porous and have the advantages of high specific areas, superior mechanical and excellent handling properties. Electrospun fibers produced from polymer solutions or melts have extremely small fiber diameter that gives rise to a large surface area (∼100-1000 m2/g). Large surface area improves the diffusion of solvents and reagents, and makes the fibers excellent candidates as carriers and supports for reactive compounds. Moreover, if a nanoporous texture is added, the high surface to volume ratio can easily surpass that of silica gel (400 m2/g). These properties are of particular interest in some biomedical applications, such as tissue engineering, drug delivery, and immobilization of antigens and proteins.; A review of the relevant reactions and electrospinning techniques for polymers and copolymers of styrene is given in Chapter 1. Various reactions have been employed on styrene and particularly the benzene rings as well as on the maleic anhydride to obtain specific functional groups and create new materials. Electrospinning has been in large interest to create efficiently ultrafine fibers with high surface area from synthetic and natural polymers.; Chapter 2 describes the fiber formation from polystyrene (PS) and poly(styrene maleic anhydride) (PSMA) by the process of electrospinning. PS has not been extensively used to produce nanofibers but has been widely used as Merrifield resins in the form of micron size beads. Although PS beads can be useful in several biological applications, PS nanofibers would be even more useful because of their large surface area, superior swelling and absorptive properties. PSMA has been rarely electrospun into fibers although present interesting properties with its highly reactive maleic anhydride moieties. Maleic anhydride is a monomer that is commonly used to add hydrophilicity to polystyrene backbones, and create chelating ion exchange supports. The efficiency of the fiber formation and the morphology of fibers and pores were investigated. Solutions containing two solvents with differential rates of evaporation and different solubility characteristics were prepared to alter the surface morphology of the fibers. (Abstract shortened by UMI.)...