We have seen before that silanization slows down discoloration and hence prevents membrane degradation. In Sepcon, the sample should last over a week. Further, it was necessary to check whether silanized surface supports normal cell growth. Therefore, comparison of cell adhesion on aminosilanized surface is made to control surface (non silanized). I took samples from…
This is a continuation of the last post on AFM analysis of pore changes during discoloration. I took the AFM images, inverted them in ImageJ so that the pores would be white and then did PoreProcessing in MATLAB. I simply selected a threshold but did no binary operations. The calibration for these AFM images was…
To complement the recent study which investigated pore changes during discoloration with TEM, I did AFM on the same samples. These were w673 samples which were incubated in DMEM (-FBS) in the 37C oven. We didn’t use FBS because I thought the serum proteins would have adsorbed to the samples and then made AFM analysis…
As seen before, in 2D format ‘RTP+silanization’ helps. Similarly in 3D format, with membrane side down, the same treatment helps prevent discoloration till 5 days. (samples from W413) Above figure shows how combined effect of RTP and silanization is better than just RTP/Silanization or none. (the weird discoloration pattern could be a result of few…
Chris gave me a few wafers to look at with AFM – an oxide sputtered in the recently cleaned chamber and VA Semiconductor wafers cleaned with “Normal Power” or “Full Power” Megasonics. I employed a couple of new “tricks” to help with the imaging this time. All of these scans were taken almost entirely in…
In continuation of the previous post, I ran the pore processing software for two samples (t=0 and t=150 min). The following histograms show the pore parameters and the difference in the pore size and numbers between the two samples. I am not sure if the difference between the pore sizes could be due to sample-sample…
There has been uncertainty with process of dissolution of pnc-Si in cell growth media. Whether the media enters the pores and ‘eats away’ the material leading to increase in pore sizes and eventually complete degradation was the question. Thinning of the material would have taken place too. To have a clear picture about this, I…
A few of the newest SC wafers came back with intact samples without any pinholes. First here is a list of the experiments that we want to do in our lab with intact/pinhole free membranes 1. Protein separations – Requires >10 samples per wafer (preferably even more) for replicates of separations in both pressure and…
In the last few weeks, the production team has focused on making strong, stable, porous material with the AJA sputter system. In the process, we’ve RTPed a wafers over a wide range of temperatures under different deposition conditions. We found that it’s possible to make membranes that range from non-porous to highly porous along with…
Lately, Anant and I have been doing our discoloration experiments under purposely harsh conditions so we don’t have to wait for multiple days for experiments to finish. We have lots of evidence that the 3D format slows down discoloration (post1, post2, post3). This experiment was to test how long samples will last in 3D format…