During the past few weeks, I have been experimenting with different array setups for diffusion. I have been working with BSA, but I will move to APOBEC3G protein once the arrays Barrett designed are finished. All of the pnc-Si arrays…

I’ve tested several membrane types with the streaming potential apparatus in order to calculate zeta potential.  Here are the results: All materials in the above chart have negative zeta potentials.  Pnc-Si seems to have the highest overall potential, followed by…

Chris asked me to do some scans of samples last week but I didn’t have time to get to them.  I was able to scan them today since I was setting the AFM up for my class anyway. I took…

Today I tried to pass 5 nm gold through three different membranes with similar cut-offs but distinct mean diameters and porosities.  All the samples I used were ozoned yesterday and tested for water permeability. Based on the absorbance measurements, it…

I tested four membranes with different porosities today, including one that had been carbonized.  Here are the pore size distributions with TEM micrographs. I ozone treated all the samples prior to running the experiments, including the carbonized sc 582.  I…

Last week, I finished up an initial experiment to investigate whether pnc-Si membrane geometry affects cell morphology.  To do this, I used a mask with 2×2 arrays of different size squares and also samples with 4 slits of different lengths…

I did two tests using water straight out of the Barnstead and with water from the cleanroom in Hopeman.  I was able to maintain high permeability using the same membrane for at least three successive trials with both.  It looks…

Hi all! Above is an image of the bioreactor made from the square, 5-slit pnc-Si chip and a PDMS structure.  Fused-silica capillary tubings were inserted into the bioreactor to form the inlet and the outlet for the transfer of the…

I’ve become increasing suspicious of the membrane clogging during the hydraulic permeability experiments.  I ran an experiment where I took three fresh samples (sc 582) and pushed water through for 5, 10, and 20 minutes.  Ideally, the permeability would be…

Looking back at production over the last year, I noticed that our porosity has dropped considerably.  Now that we have a good handle on controlling pinhole density, it is time to focus on controlling morphology again.  Below are two examples…