Barnstead and Hopeman water OK
I did two tests using water straight out of the Barnstead and with water from the cleanroom in Hopeman. I was able to maintain high permeability using the same membrane for at least three successive trials with both. It looks like the culprit is the Nalgene container used to store the water. For any sensitive experiments, I would recommend dispensing straight from the Barnstead.
It would also appear that the PDMS gasket does not leech enough material to clog the pores over the three trials (1 hour, ~800 uL).
Are these ozone treated with no ethanol soak? I’d say they are definitely well-wetted.
Has anyone else been using water from that container for forced-flow experiments (it doesn’t matter if it is autoclaved)? IF so, they need to be repeated.
Is the small fall off in the hopeman samples real? There may be too few samples to draw a conclusion, but it looks like there could still be some clogging from PDMS or other contamination. I’m much more comfortable now that we are at least in the vicinity of the theoretical value. It would be good to repeat the PBS buffer (not made with bad DI water) and DI water flow experiments, as clogging could have been the difference in flow rates. Carbonized samples are probably also in the queue?