used for the first two coatings on snpcm 83 while the third and final coating was just the pfa acetone solution twenty five weight percent peg with a molecular weight of 1500 and 900 were each prepared in 30 wt pfa in acetone the homogeneous solutions were used to coat snpcm 85 and 86 respectively a new ultrasonic horn operating at 60 khz was used for preparing snpcm 95 snpcm 96 was pyrolyzed in a hydrogen environment rather than helium sncpm 97 like snpcm 73 and 74 was prepared with a higher concentration of high pore silica zeolite 15 wt in pfa and acetone finally snpcm 511 is one of our first attempts to scale up the membrane area from our previously described support area to a tubular support with an outside diameter of 12 7 mm and a porous length of 150 mm after completion of each heat treatment the furnace is shut off and the tube assembly was allowed to cool in the oven under flowing helium except for snpcm 96 which was cooled undered a hydrogen atmosphere during the entire pyrolysis process the quartz tube was purged with helium at a flow rate of 100 sccm or in the case of snpcm 96 hydrogen at 100 sccm this pyrolysis protocol followed that used for synthesis of unsupported npc d s lafyatis.