Because our membranes are not mono-disperse, we often debate the relative contribution of large pores vs small pores in both diffusive and convective separations. Indeed it is possible that the way pores contribute to transport in these two modes is…

I think some of us have been confusing each other in our discussions of the dependence of flow rate on pore radius. Jim thinks in terms of a single pore, and I agree that there is an r^4 dependence. Therefore,…

15um beads on discolored membrane surface, having some slits where the beads are not found The localization of microbeads suggest that they have fallen across the slits in the membrane Transparent membrane with microbeads on its surface These membranes are…

Dave and I characterized the membrane samples using the 4-point probe system at Kodak research Lab. It is NOT the previously discussed micro-4-point probe. The spacing between two probes is about 2mm. We first tested a quarter bare wafer#388 at…

5nm BSA-Au appears to be 12.7nm.10nm BSA-Au is 18nm. Dilution dependent size change of 5nm BSA-Au. One theory for the size change was that residual BSA was combining with the Au peak and for some reason dilution of the BSA…

The Ozone generator works very nicely. Dave is going to be providing an in-depth user manual for us, so I’ll be somewhat brief. In this first picture, I compare an ozone treated sample against a control. Both ‘droplets’ are 3uL…

I tested five types of track-etched membranes (with pore diameters 0.1, 0.08, 0.05, 0.03 and 0.01micron). All of them are 6micron thick and usually have 14-16% porosity. First experiment was to confirm the official air flow rates data with our…

These are low burst results but samples have lots of pinholes on them many of which are on the edges. I also checked porosity of the wafers 338 and 340. They indeed have porosities close to 7%. Wafer 340 (0,5)…

w312 Number of Pores HistogramContributed Area Histogram 5nm BSA-Au is detected in the filtrate after 24 hours. 10nm BSA-Au is not. The 5nm registers around 10nm after conjugation and the 10nm is closer to 15nm. This selected membrane is not…

Wafer 403 was processed last week using the new thermal oxide/TEOS steps outlined in the previous posts. I took images from six positions at different radial positions on different axis. All six samples looked relatively uniform! (1,0) – 35kx (0,-2)…