I continued work with a couple of new wafers and settled on one that lowered the cut-off to between 5 and 10 nm gold particles. For completeness, I will also include some of the old data that has been further analyzed. All experiments were performed with BBI stock gold solutions (0.01% w/w?) diluted 1:1 with…
I had some old carbonized samples kicking around and decided to do some high res TEM yesterday to see what a completely occluded pore looked like. Below is an image showing a blocked pore and adjacent Si nanocrystal. Inside the pore, you can see concentric “rings” of carbon atoms i.e. graphene sheets? Here is a…
I took a look back through the Melvern data I collected, particularly focusing on changes in the intensity data in the BSA-DDM solution (the previously posted plots were of number data). When I compared the peak intensities for BSA, DDM, and DDM-BSA complex I noticed that the intensity peaks fall over the same size distribution…
Yesterday I used the Melvern to determine particle size and zeta-potential for BSA in DI-water. For the particle sizing I used a concentration of 2mg/mL but I had to increase the concentration to 10mg/mL in order to get an accurate zeta-potential measurment. As shown above the size measurements provided an average diameter of approximately 5.6nm….
This previous post contrasted how gold could be separated by pressure in deionized water, but not by diffusion (w199). I checked up on that diffusion sample again after 6 days, and while the retentate had mostly evaporated, there was no gold within the remaining filtrate. As you may recall, there has been some discrepency with…
Last week during the deposition step, Chris and I discovered that part of the Cu “power cup” (piece that is bonded to target to make thermal contact with sputter gun) had eroded and coated the inside of the target shield with copper. Later EDX and TEM characterization showed that there was indeed contamination in the…
The deposited metal thickness is 20nm, consisting of 10nm titanium and10nm gold. Post not finished. sc b020 – 25nm sc b011 sc b01
A paper by Munch (from Kodak), Zestar, and Anderson in J Mem Sci (1979) writes that charge has a big effect on albumin separations in track etched membranes. They show in their paper that they can make the theoretical sieving match the results better if they simply add the Debye length to the molecular radius…
This is the first post I have made with respect to the project proposed by Mark Dumont of the department of Biochemistry and Biophysics. As a reminder of the scope of the project Mark has shown an interest in using our pnc-Si membranes to separate detergent from trans-membrane proteins during the process of preparing samples…
I set up diffusion experiments using the wafers that Tom was able to pass gold through in DI H2O using pressure. 5nm particles do not pass in 24 or 48 hours. If we have extra samples I will be testing 5nm particles in 10mM KCl.