Degradation Processes in Corona-Charged Electret Filter-Media with Exposure to Ethyl Benzene

The degradation of filtration performance for corona-charged electret filter media exposed to ethyl benzene was assessed. Nonwoven corona-charged polypropylene fiber mats were exposed to ethyl-benzene using a custom made apparatus. Evaluated scenarios included ethyl-benzene vapor and liquid exposures. The filtration performance was evaluated using DOP as a test aerosol to measure filtration performance. It was observed that significant filtration degradation occurred only when liquid ethyl benzene came into direct contact with the filter media. No significant changes in the pressure drop or filtration efficiency was observed for any of the exposure scenarios in which the fibers were only exposed to ethyl benzene in the vapor phase.