Pressurized rerun with w670
The previous w670 pressurized flow gels showed one trial with a lower cutoff than w673 and one trial with nothing passing through. This experiment was run for 40 min and in each case I saw only 0-3 uL fluid passing.
I used the last couple of samples from this wafer to attempt a more conclusive pressurized flow run. Two trials were run at 2 psi for 80 min, and about 3-6 uL passed in each case. I was also careful to seal the samples during this run to limit evaporation. Here are the results:
It is clear that not much is passing through these membranes, however it seems that there are two different cutoffs in these trials. With somewhat close r-values, I wouldn’t expect radial changes in the porosity/pore size to be an issue. Maybe one had just better permeability than the other. The first trial has similar results to what I saw in the previous post.