Degradation testing membrane

Figure 20. Strain-to-break for Nafion 117 (left) and NRE-212 (right) membrane samples before and after Fenton degradation test.

Bae, S.J., Kim, S.-J., Park, J.I., Lee, J.-H., Cho, H., and Park, J.-Y. (2010) Lifetime prediction through accelerated degradation testing of membrane electrode assemblies in direct methanol fuel cells. Int.J. Hydrogen Energy, 35, 9166-9176. Shao, M. (2011) Palladium-based electrocatalysts for hydrogen oxidation and oxygen reduction reactions. J. Power Sources, 196, 2433-2444. 

For both gel contents and qualitative solubility tests, membrane samples of similar thickness are immersed in the respective solvent, and kept at a fixed temperature for a fixed period of time, typically a few days. After the test, the membrane sample is dried and weighed to give ( residual- If the Solution is stirred, care must be taken that the membrane is not hit by the stirrer to prevent mechanical degradation. For this purpose, the membrane samples can be protected by a sieve or wire mesh. In case the membrane disintegrates the solution can be filtered and the dissolved portion can be determined by evaporation of the solvent. 

Bae Suk-Joo, Kim Seong-Joon, Park Jong, 2010. In Lifetime prediction through accelerated degradation testing of membrane electrode assemblies in direct methanol fuel cells. International Journal of Hydrogen Energy, 35(7) 9166-9176. 

Results from a series of degradation tests on grafted polystyrene sulfonic acid (g-PSSA) membranes have shown that thinner membranes have higher degradation rates than thicker ones (Gubler et al. 2005). Divinylbenzene cross-linked membranes have higher durability than non-cross-linked membranes owing to their lower gas crossover rate. 

PPS fiber has excellent chemical resistance. Only strong oxidising agents cause degradation. As expected from inherent resia properties, PPS fiber is flame-resistant and has an autoignition temperature of 590°C as determined ia tests at the Textile Research Institute. PPS fiber is an excellent electrical iasulator it finds application ia hostile environments such as filter bags for filtration of flue gas from coal-fired furnaces, filter media for gas and liquid filtration, electrolysis membranes, protective clothing, and composites. 

Stndies of the antoxidation of carotenoids in liposomal suspensions have also been performed since liposomes can mimic the environment of carotenoids in vivo. Kim et al. stndied the antoxidation of lycopene," P-carotene," and phytofluene" " in liposomal snspensions and identified oxidative cleavage compounds. Stabilities to oxidation at room temperature of various carotenoids incorporated in pig liver microsomes have also been studied." The model took into account membrane dynamics. After 3 hr of reactions, P-carotene and lycopene had completely degraded, whereas xanthophylls tested were shown to be more stable. 

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