Permeability and Ozone Treatment
I treated samples from w312 using our ozone equipment. Quickly, here was the protocol:
Place samples in chamber
Turn on O2 and supplemental Ozone generator
After 3 mins, turn on Lamp in main chamber for 5 mins (Heater set to 110C)
Leave samples in chamber for 15 minutes after timer turns off
(O2 and supplemental Ozone should still be on)
Turn of O2 and Supplemental Ozone
Hook up vacuum line and turn on vacuum for 30 seconds
I was planning on performing a specific set of experiments, but some samples failed, so here is what I have left:
There are a few ambiguous conclusions that we can draw:
1. Permeability decreases with time after ozone treatment
OR – running DI H20 through the sample reduces permeability because debris clogs pores
2. The membranes are not as permeable to PBS as DI H20 – Since the R=5 permeability recovered at 22hrs and was the same percent higher than R=3.6 and 4.5, it seems hard to say that something in the PBS clogged or modified the pores. More experimentation is certainly necessary.
3. These values are about 2-3x higher than for w310 which was made very similarly and had similar pore sizes according to TEM. However, those samples were run with PBS. If you compare the only PBS run here, it is similar. Again – more experiments needed.