Permeability was calculated with Dagan theory for membranes in this post. Pore processing was performed and r.mat files were run through the programs used to calculated permeability in submitted Science paper. No Carbonization Experimental: 591 ul/(min*PSI*cm^2) Theoretical: 801 ul/(min*PSI*cm^2) Carbonized (6.2 nm taken out of diameters) Experimental: 289 ul/(min*PSI*cm^2) Theoretical: 438 ul/(min*PSI*cm^2) It seems that there…
A simple hydraulic permeability study was performed to determine whether carbonization would negatively impact water transport through the membranes. 5 slit square SepCons from SC 471 were carbonized and put in the ultra-centrifuge with a 500 uL starting volume. The samples were spun for 10 minutes at 3000 RPM (equiv to 4.95 PSI starting). SC…
SiMPore has been collaborating with the Infotonics Center to scale our SepCon production to a 6-inch wafer. The wafers are patterned and deposited at their facility and then brought back to UR where we anneal and etch. This week, we etched several wafers and the initial results look promising. The big news is that we…
I’ve suspected that the barrier function of endothelial cells might be surface-dependent (that is, cells grown on the pnc-Si side vs. cells grown on the well side). I hypothesized that the interface between membrane and well walls would alter the continuity of the endothelial monolayer when cells are grown on the well wide. To test…
Using streaming potential data collected via the flow device Jess created, I have attempted to recreate the Zydney findings for membrane zeta potential. Ag/AgCl electrodes were used in 10mM KCl, mimicking identically the method outlined in Zydney. Data are below: The streaming potential for both trials of PES membranes varied significantly after 60 minutes in…
During the last production run, we experimented with varying the RTP annealing time (1 min vs. 5 min) at three different RTP temperatures (1050 C, 1100 C, 1150 C) in a 30 nm thick membrane. Below are the TEM micrographs with corresponding histograms and average pore diameter/porosity plot. Of note is the 1050 C anneal…
The human IgG did not seem to diffuse through the membrane the first time we conducted a diffusion experiment. Barrett believed that the lack of diffusion was most likely due to protein aggregates blocking the pores. So, the human IgG was filtered, and this post is the result of a second round of diffusion experiments….
During the history of pnc-Si fabrication, we have always observed that pore formation is intimately related to the crystallization process. In general, large nanocrystals in a film correspond with larger pore diameters. A partially crystallized film will have a low density of films. Following the work that describes crystallization of a-Si in terms of kinetic…
In my last couple of posts with respect to endothelial cell culture on pnc-Si transwells, I presented images of cell clumps over the active pnc-Si membrane area of transwells (here and here). There were dead cells associated with these clumps and this is a concern for barrier function experiments. This post shows a counter-example of…
I’ve repeatedly seen cytotoxic edge effects when I grow bEnd3 cells on the bottom of PET membrane transwells. Here’s a post of images. I’m getting closer to co-cultures of bEnd3 and NG108-15 cells on opposite sides of membranes and I’ve been investigating the optimal arrangement of the different cell types (bend3 on top or bottom?). …