Henry and I just got back from our meeting with Dean over at RIT to talk with him about the production process for making our proposed flow dialysis system. While we were there Dean described in detail the entire production process including the anodic bonding and the parylene deposition. We also returned with membrane samples…
I recalculated the permeability of the track-etched membranes using Poiseuille’s Law this time assuming that the pore diameters specified by Sterlitech are smaller then the actual pore sizes. For the first recalculation I assumed that the “real pores” are 20% larger then specified by Sterlitech. As shown above the resultant Poiseuille’s Law predictions are much…
I constructed a plot of hydraulic permeability based on the flow rates that Sterlitech has predicted for their membranes. Looking at the permeability values that I posted last week, outside the tested that appeared to leak, there was a 0.01um membrane with a permeability of 33.4, two 0.05um membranes with permeabilities of 59.9 and 71.1,…
I ran some tests today using the 0.01um, 0.05um, and 0.10um pore diameter track-etched membranes from sterilitech. The tool the paul built to cut the membranes works very well, and assembly into the microcon systems it simple. I used the standard vertical-wall o-rings that come in the microcon systems because based on yesterdays test results…
This morning I did a little work with the track etched membranes (0.05um 13mm). I talked with Paul over in Hopeman and he is currently working on making a small coring tool to cut out the membranes (it should be done by the end of the day). In the mean time I figured out that…
I briefly experimented with the track-etched membranes this morning and found that they are extremely fragile and near impossible to cut. I disassembled a few of the microcons and found that a circular piece of paper the size of a hole punch (like the one on the bench by the mac) fits perfectly into the…
I retested the 100K Microcon, 100K Nanosep, and 300K Nanosep membranes at 1000RPM, which in the clinical centrifuge is 4.33psi by my calculations. I retested the 100K Nanosep just to make sure that we had some solid permeability values. I retested the 300K Nanosep because of the extremely low permeability I calculated for the first…
Just to double check the numbers I calculated on Tuesday I ran some wet-wet trials with 100K and 300K Nanoseps. Based on the wet-dry results we would expect that the permeability for the 100K Nanosep would be higher than that of the 100K Microcon. It goes without saying that the 300K Nanosep would also be…
A while ago I made a post about the permeability through the 100K microcons in the wet-wet EQ format. I had run three membranes, and stopped (and restarted) the centrifugation at three separate time points to be able to calculate three permeability values for each membrane. When I did this I got strange results; the…
Earlier in the week I retested the 100K microcons in our wet-wet EQ format. When I last ran them this way I calculated very little flow and very small permeability values. I noted that there was a rather large air pocket collecting on the underside of the membrane in the plastic support structure; most likely…
