Tom prepared two PVP coated TEM samples for me to image today. One of the samples was washed with dH20 and the other left untouched. Below is a series of three images, from left to right: no PVP, PVP no wash, PVP & wash. I wasn’t able to tell any differences under the River Campus…
I recalculated the permeability of the track-etched membranes using Poiseuille’s Law this time assuming that the pore diameters specified by Sterlitech are smaller then the actual pore sizes. For the first recalculation I assumed that the “real pores” are 20% larger then specified by Sterlitech. As shown above the resultant Poiseuille’s Law predictions are much…
We’ve recently put together our own protein ladder, which contains myosin heavy chain, beta-galactosidase, phosphorylase b, IgG, albumin, and cytochrome c. This is my first attempt running this ladder on w398, one of the new pinhole free membranes. From the TEM pics, it seems that w398 has pores all around the 50nm range, which is…
Chris and I got to play on the new Zeiss scanning transmission electron microscope (STEM) today (learn about STEM here). We didn’t get to spend a lot of time on it, but here are some quick images we snapped. wafer 416 @ 25kx (left) and 65kx (right) Even though we’re imaging in transmission mode, the…
The new bottle of PVP (polyvinylpyrrolidone) sitting on the shelf was calling my name this morning. I apologize that this post is long, but its pretty exciting – I think we have half-solved the wettability problem. According to MSDS sheets, PVP is soluble in water and alcohols. Since drying water on the membrane is a…
Below is an image of HUVEC grown on RTP treated W303 for 72 hours. The cells were seeded at high density and therefore reached confluence prior to day 3. The first row shows the membrane area of the sample; the membrane is not intact. The second row shows the edge of the sample. Live and…
Wafer 416-T is a TEOS wafer annealed at 900 C. Pinhole density is relatively low. left: (1,0) @ 35kx; right (0,4) @ 35kx left: (1,0) @ 50kx; right (0,4) @ 50kx
TE membranes were first embedded in plastic material and then these samples were cut with microtome and imaged. The images below are of the 30nm and 80nm pore diameter membranes. 30nm ones came out better. It looks like the diameter isn’t really 30nm, look at the second picture. The dark spots are either tears or…
Wafer 398 was deposited on 2/14/2008 but just etched yesterday in the new cell (it’s a beauty esp. when you compare it to the old one). I’ve etched several wafers now in the new cell and none of the membranes show signs of cigarette burns or tears. Good news in regards to the copper contamination…
Wafer 415-T has been delivered to the lab. It was processed with TEOS and annealed at 950 C. There are a few usable samples, especially along the edge of the wafer. Pinhole density increases as you move towards the center. The uniformity across the wafer is good. From left to right, top to bottom: (0,1)…