| 초록 |
The basic requirements for commercialization of proton exchange membrane (PEM) are high proton conductivity and outstanding mechanical properties. Here we showed an effective way to improve membrane performances by co-solvent technique. When sulfonated poly(ether ether ketone) was dissolved in low dielectric constant solvent (ε=30-40), the addition of high dielectric constant solvent (ε=78) induced the changes in polymer nanostructures due to strong hydrogen bonding interaction with sulfonic acid groups, which resulted in expanding nanochannel and crystalline domain of PEM. By adding high dielectric solvents, the size of nanochannel increased from 5.4 to 6.8 nm. Hence, the proton conductivity also increased up to 28%. Moreover, the crystalline domain was well aligned, which led to increased tensile strength of PEM. Finally, fuel cell performance showed 24% increased power density compared to the pristine membrane, which will certainly open up the new way for commercialization of PEM. |
