Suleiman Rosado, DavidOcasio Velázquez, Mayra2018-05-162018-05-162004https://hdl.handle.net/20.500.11801/621Over the past years, one of the most important challenges facing industry has been the search for environmentally benign and cost effective alternatives to traditional power sources. Many industries invest considerable amount of resources to develop and implement new methods of power production. One of the new technologies under consideration is a proton exchange membrane fuel cell (PEMFC). Nafion is the best-known ionomer membrane used in fuel cell and electrolysis applications due to its excellent chemical and mechanical stability and to its high ionic conductivity. The purpose of this work was to investigate the effects of supercritical fluid processing on the physical properties of Nafion and Styrene-ethylene-butylene-styrene (SEBS) ionomer membranes. Various co- solvents, with different solubility parameters, were employed in the search of improving polymer- scCO2 interaction. In this study, the properties of Nafion and SEBS polymers were investigated by thermal gravimetric analysis. Changes in the degradation temperature of Nafion and SEBS membranes were found as function of co-solvent and processing conditions used.enProton exchange membrane fuel cell (PEMFC)Supercritical fluid processingNafionFuel cells.Ionomer.Ion-pemeable membranes.Supercritical fluids extractions.Thermogravimetry.Membranes (Technology)Proton exchange membrane fuel cells.ThesisAll rights reserved(c) 2004 Mayra Ocasio Velázquez