Date of Award
8-1-2005
Document Type
Thesis
Degree Name
M.S. in Engineering Science
Department
Chemical Engineering
First Advisor
Dr. John O'haver
Second Advisor
Dr. Clint W. Williford
Third Advisor
Dr. Ajit Sadana
Relational Format
Dissertation/Thesis
Abstract
Surfactants in aqueous media can form a variety of microstructures such as micelles of various geometries, emulsions, microemulsions and vesicles. Cetyltrimethylammonium p-toluene sulfate (CTAT) has been found to cause large increases in solution viscosity in certain concentration ranges. This phenomenon has been ascribed to the formation of wormlike micelles. Using this, we have synthesized polystyrene nanofibers by emulsion polymerization in wormlike CTAT admicelles in the presence of added sodium chloride (NaCl). Polystyrene nanofibers approximately 3 µm in length and 20~ 60 nanometers in width, were created by emulsion polymerization at 50°C for ten hours using 2, 2’-azobis-isobutyrInitrile initiator. The impact of styrene loading, surfactant concentration and the amount of added salt on the nanofiber characteristics was examined. Separate nanofiber strands were imaged and analyzed via atomic force microscopy (AFM), showing tightly coiled nanofiber strands of various sizes deposited on a polystyrene substrate. When the fibers were deposited on mica, linear polymer strands were observed. AFM can provide information not only on the shape and size of the polymer nanofibers, but also on the size distribution of the nanofibers. Gel Permeation Chromatography (GPC) was used to provide information on polymer molecular weight and molecular weight distribution. The average molecular weight range is from 400 to 800 Daltons. The low molecular weight is probably the result of the relatively high AIBN to styrene ratio. Thermogravimetric Analysis (TGA) was used to determine the polymer decomposition temperature and percentage of each component.
Recommended Citation
Wei, Suxiang, "Synthesis and characterization of polymer nanofibers produced by emulsion polymerization" (2005). Electronic Theses and Dissertations. 3496.
https://egrove.olemiss.edu/etd/3496