Summary: We analyzed quantitatively the effects of temperature on the morphologic evolution of the desorption process in hot water measured ex situ by atomic force microscopy. The morphology of the hole that forms with immersion of the polyelectrolyte film in hot water has characteristics similar to those from polymer dewetting processes near the glass transition temperature. The hole diameter immediately reaches a maximum in the desorption process while the number of holes increases linearly with time.AFM images of the morphology of PEM film after immersion in hot water 60 min.magnified imageAFM images of the morphology of PEM film after immersion in hot water 60 min.

The rate constant for gas-phase reactions of OH radicals with 1H-heptafluorocyclopentene (cyc-CFCFCFCF═CH-) was measured using a relative rate method at 298 K: (5.20 ± 0.09) × 10 cm molecule s. The quoted uncertainty includes two standard deviations from the least-squares regression, the systematic error from the GC analysis, and the uncertainties of the rate constants of the reference compounds. The OH-radical-initiated oxidation of cyc-CFCFCFCF═CH- gives the main products COF, CO, and CO, leading to negligible environmental impact. For consumptions of cyc-CFCFCFCF═CH- of less than 54%, the yield of the formation of ([COF] + [CO] + [CO])/5 (based on the conservation of carbon) was 0.99 ± 0.02, which is very close to 100%. A possible degradation mechanism was proposed. The radiative efficiency (RE) of cyc-CFCFCFCF═CH- measured at room temperature was 0.215 W m ppb. The atmospheric lifetime of cyc-CFCFCFCF═CH- was calculated as 0.61 year, and the photochemical ozone creation potential (POCP) was negligible. The 20-, 100-, and 500-year time horizon global warming potentials (GWPs) were estimated as 153, 42, and 12, respectively.

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