I discussed with Jess the possibility of using a negatively charged dye. People did use such dyes before but we probably need to order them at this time. Since now we can use the spectrophotometer to determine the concentration of a solution, we might be able to make use of the potassium permanganate (KMnO4) solution…
I’ve upgraded the WordPress publisher to version 2.6. The most useful change is the ability to track changes to any post/page, compare revisions, and revert to an older version. Here’s a video showing the changes: https://videopress.com/v/mARhRBcT/fmt_std Additionally, I’ve installed some plug-ins that should make posting and keeping up with new posts easier: There is now…
As mentioned previously intact membranes show a flux comparable to membranes with pinholes during desalting experiments. To confirm this a third intact membrane test and two pinholed tests were run under the exact same conditions. Previous pinholed samples had different NaCl solution volume in the SepCon, I wanted to remove any variability caused by this….
A few weeks ago Dave dropped of a humidity monitor for the third floor equipment room. Since then I have been recording the humidity every time I run a UV Ozone process for PDMS-glass or PDMS-pncSi bonding and there seems to be a correlation between the two. Over the last week there seems to be…
Yesterday I found a bug in the pore image processor. The “i” hotkey is supposed to save the current image, but it wasn’t working. I contacted Mike Bindschadler and he fixed it. The updated version can be found here. The only change is in the “pore_processing_gui_call” .m file. Happy processing!
I tried to clean samples from W615 using UV/ozone to cleanse the membranes of the organic impurities we have been seeing lately. I followed the UV/ozone protocol, with a stage temp of 25C and treatment time of 5 minutes. No change in the impurities were observed; I plan on trying to run it again for…
Yesterday I started a test to try and reproduce the results Henry was able to obtain with a closed flow system last week. Using four samples (W619) I ran the UV Ozone bonding process and allowed them to sit over night. This morning I found that only one of the four samples was bonded; recently…
I tested W612 for air permeability and burst pressure, shown below. It should be noted that the air permeability and burst pressure values are comparable to W504; looks like a good reproduction! I also tested a sample with the hexane residue and debris, no difference in permeability or burst pressure was seen. Background pores included…
In an attempt to improve membrane life in cell culture, different RTP times were tried on a single wafer. Samples from W514 were RTPed in Ar at 800C for 1, 5, and 10 minutes, respectively. Cells were then seeded at confluence on membranes, with membrane stability monitored for breakage. Discoloration was monitored on samples without…
Just an update on the closed flow systems I put together yesterday using vacuum grease. Even with the vacuum grease at the point of entrance of the capillary tube to the PDMS-pncSi system the PDMS was able to get into the trough of the membrane chip. I will talk with Henry today to see what…