UPDATE:
A look at long and short crystal dimensions (9/1/10):
DLS vs. Crystal Sizes – Newest version 8/30/10
Here is a comparison of sieving curves using DLS or estimated crystal dimensions of proteins.
DLS:
24 hours sieving curve.
48 hours sieving curve.
Estimated longest crystal dimension:
24 hours sieving curve.
48 hours sieving curve.
We have already established that bias is an important parameter in controlling the morphology of 15 nm thick pnc-Si, but have yet to look at its effect on thicker films. This week, made a few 30 nm thick Si films with 02, 05, 25, and 50 W of substrate bias. I annealed these films at…
In collaboration with Alex Shestopalov’s lab, I started working on liquid based PEG treatment on windowed sepcon chips. The treatment is a 3-day long protocol and involves multiple washing and drying steps with different reagents. Most of our sepcon chips broke down in first few steps itself. The initial wash consists of Nanostrip (sulfuric plus nitric…
The NPN tenting mechanism I’ve described in a few different posts has relied solely on mechanical technique. I poke the substrate with tweezers, or delaminate it with high electrical forces, or heat it up and let it contract while in contact with each other. It would scale very poorly if we tried to make this…
Last week Sarah and I made several standard nanofluidic transistor (NFT) stacks (3 nm Ti, 12 nm Ag over a 3-slot SiN membrane – wafer # 1024) in the cleanroom. I then measured the zetapotential of these devices at pH 7.43, and we thought that because the outer layer of the chip was Al2O3 that the…
Here are the results of diffusion based protein separations at different salt concentrations and 50kD Microcons: We see a sharp cutoff between 31 and 45kD. Separations look like they have progressed further in 10mM salts rather than 100 mM (this is the opposite of what we see in pnc-Si). The 100kD data may also support…
Last week, I took some of Jess’ 20 nm Au colloids and placed them on a membrane for imaging under TEM. I took images at each of our standard magnifications. Using Mike B.’s pore counting program, I generated statistics and calculated the pixel-to-nm conversion ratio assuming the gold colloids were 20 nm (< 10% variation)....