| dc.description.abstract | ABPBI is synthesized successfully in this research. After synthesized , ABPBI mix with three different acid polymers PVSA, PVPA, and PAA to form acid-base polyelectrolyte membranes. FT-IR and XRD data show that the compatibility between acid and base polymers is high because of the acid-base interaction, Besides, after adding small amount of acid polymer in ABPBI, the regular arrangement of ABPBI is destroyed because of the acid-base interaction. The interaction between ABPBI and PVSA is the strongest of all the membranes, even the 50ABPBI-50PVSA is similar to the formation of salt. All the membranes have high thermal stability up to 200℃, it means that the membranes can be used safely in high temperature fuel cells. If acid and base polymers mix well to form an ordered structure, the decomposition temperature of functional groups is increasing, and the thermal stability is higher.
Variable temperature conductivity for dry membranes follows the Arrhenius law. With the increase of temperature, the proton conductivity is increasing. In ABPBI-PVPA system, 50：50 ratio shows the lowest proton conductivity. High resolution solid state NMR shows that ABPBI and PVPA form a compact complex when the ratio is 50：50. This result suggests that the proton is more easily to transport in this membrane. In the wet condition, proton conductivity increase with increasing temperature before water loss temperature. When water starts to vaporize, proton conductivity drops quickly, it means water is the major medium to transport proton in membranes. According to the data above, the hopping and vehicle mechanism to transport proton both exist in membranes, and ABPBI-PVPA system shows the highest proton conductivity in dry and wet conditions. It means the interaction between imidazole and phosphonic acid is suitable for proton transport. | en_US |