I am in the process of inspecting each membrane in the newly created wafer 612. First of all, some samples (~10% counted so far) have tears on the membrane edges, shown below. Images were taken at 20x microscope magnification (reflection image followed by transmission). I also have been seeing circular defects which do not penetrate…
Just an update on the PDMS-pncSi closed flow systems progress… The issues we were having early last week with bonding seem to have been solved. We used to run extra ozone flow for ten minutes after the initial 5minutes of UV Ozone. As it turns out this is unnecessary, we are able to get nearly…
I re-ran the rhodamine dilutions narrowing in on the molarities within the range readable by the spectrometer. My start sample was .5mM of Rhodamine. The wavelength I set the spectrometer at was 530nm with 3 trials of each dilution. I started with the least concentrated dilution and cleaned the cuvette between every trial so as…
We’ve built a set up for this but it’s not incredibly user friendly right now. It consists of a camera and a stage. Using the macro function of the camera you can take a close up image of the chip, but you must make sure the horizon line is straight i.e. camera and stage are…
Here is a summary of results for membranes (w510X) that have been annealed without their protective oxide. 800 C RTP @ 10 C/s in susceptor 850 C RTP @ 10 C/s in susceptor 900 C RTP @ 10 C/s in susceptor 950 C RTP @ 10 C/s in susceptor It seems that annealing between 800…
I fixed the graph for the serial dilution of Rhodamine that I did last week and removed all absorbency values that were greater than 1.08 AU. The graph looks much more linear now with an R^2 value of .9517
I took a sample from w304 over to the Krauss Lab and had them try to image it with AFM. Here are a few pictures (for some reason the color scales weren’t included in a couple of them, but they go from 0-dark to 5-light nm): In both images you can surprisingly see the pores….
I ran a series of serial dilutions with the rhodamine, to find the absorbency using the spectrometer. Below is a graph of the concentration of rhodamine versus the absorbency. I removed the concentrations which had absorbances greater than 1.7 AU because those absorbencies created a greater deviation. The lower concentrations show a more linear distribution….
Last week Jess helped me set up the diffusion cell with human albumin and cytochrome c. We ran 3 cells and used membranes from wafer 565. The membranes used were -1,4 (retentate 1), 3,3 (retentate 2), and 4,2 (retentate 3). The gel is posted below: The columns are (from left): Protein, control, retentate 1, filtrate…
As Jim suggested, we are not only going to reproduce what Chris and Tom did in the Nature paper but also trying to test the charge screening effect based on different salt concentrations. To do such experiments, we need to charge our Si membrane and at the same time oxidize it. At the end of…