High temperature proton conducting materials and fluorescent-labeled polymers for sensor applications

Abstract

HIGH TEMPERATURE PROTON CONDUCTING MATERIALS, AND FLUORESCENT-LABELED POLYMERS FOR SENSOR APPLICATIONS September 2009 SURANGKHANA MARTWISET, B.A., MOUNT HOLYOKE COLLEGE M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor E. Bryan Coughlin The majority of this dissertation focuses on proton conducting materials that could be used at high operating temperatures. Higher operating temperatures are desirable as they will increase fuel cell efficiency, reduce cost, and simplify the heat management system. The factors governing proton conduction including segmental mobility, protogenic group identity, and charge carrier density were investigated on a variety of polymers containing 1H-1,2,3-triazole moieties. Proton conductivity measurements were made using AC impedance spectroscopy. Random copolymers and terpolymers of triazole-containing acrylates and poly(ethylene glycol)methyl ether acrylate (PEGMEA) have been synthesized. Conductivity increased with increasing degree of PEG incorporation until reaching a maximum at 30% mole PEGMEA. In comparison to benzimidazole-functionalized polyacrylate with 35% mole PEGMEA, the triazole analog showed a higher proton conductivity, and a less pronounced conductivity temperature dependence. Further increases in conductivity was achieved through the addition of trifluoroacetic acid. To study the effect of charge carrier density on proton conduction,