Investigation of Proton Conductivity of Cation-Exchanged, Sulfonated Poly(b-Styrene-b-Isobutylene-b-Styrene) Membranes
Final rept. 1 Jun 2007-1 Jun 2009
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
In this study, membranes made with highly sulfonated 81-97 polystyrene-b-isobutylene-b-styrene polymer were exchanged with a variety of cations Cu, Ba, Zn, Cs, Ag, Ca, and Mg. Absorption levels of the cation-exchanged materials was determined for water, methanol, and an equimolar watermethanol mixture, measured using a gravimetric technique. Proton conductivity of the membranes was measured in a dry state, as well as swollen in water, methanol, and the equimolar water methanol mixture. Water-swollen membranes showed proton conductivity in the range of 2 x 10sup-3 to 1.2 x 10sup2 Scm, depending on the cation used for exchange. Conductivity increased proportionally to amount to the water molecules present in the membranes. Different cations promoted different levels of water absorption, with Cs and Ag having the highest amounts of water and conductivity, presumably because these two elements had only one valence electron compared to others used in this study.
- Inorganic Chemistry
- Organic Chemistry
- Electricity and Magnetism