NRG

A couple weeks ago, I posted some pictures that showed a non-linear “dose-response” curve for NaHCO3 and discoloration in the incubator (post).  I repeated this experiment at 37C in the benchtop oven.   These pictures show that there was a NaHCO3 concentration dependence on the discoloration rate in the oven.  In the 2nd set of…

Bernhard Group: Discoloration was observed during DNA separation experiments.  Further study led to these results: No discoloration observed with low pH buffered NaCl. Discoloration with high pH buffered NaCl. Worried that Cl was the culprit, sodium acetate was tested.  Discoloration observed with sodium acetate. In one early experiment, 4 areas were tested on one chip. …

Since Jess saw discoloration last week within a day in PBS with the new material, I did a couple of discoloration studies this week.  I looked at wafers 670 and 673 and compared them to 625, 704 and 680-T.  These were not RTP’ed, I did the tests at RT since that’s the temp diffusion studies…

I got back on the AFM today to rescan the wafers from yesterday and too scan a wafer that Dave had given me a few weeks ago.  The 2 panels are from the height channel, I used the 240 tip (yesterday I used the 160 tip).  The top panel is the wafer from Dave and…

I posted some pictures yesterday from AFM last week.  I got back onto the AFM today and re-scanned the megasonics cleaned virginia semiconductor wafers.  For each image, the top and bottom panels are the height and ZSensor scans, respectively.  All scans are 10um x 10um.  I did a linear analysis of the ZSensor data for…

Because of the recent discoloration problems I observed with 24 hour diffusion using w670 and 673, I decided to try a shorter time point. 673 had a couple more samples to spare, so I tried an 8 hour diffusion experiment.  No discoloration was observed: This is the normal color of the wafer.  Slits were not…

I got some wafers from Chris last week(?) that had undergone different Megasonics cleaning treatments by the manufacturer.  We’re trying to figure out if these treatments are actually cleaning the wafers.  I’ve been having trouble getting the AFM to stay in the “right” mode for imaging with these wafers.  However, I have gotten some images….

While wafers 670 and 673 did not hold up to diffusion experiments, they were strong enough to perform pressurized separations using the pressure cell.  Each experiment lasted for 40min, although the average flow was only about 5ul for this duration. 673 has a pore cutoff around 30nm (refer to Dave’s post).  The following gel shows…

I’ve processed all the images used in the water permeability studies and found the following statistics from these images: Mean Diameter Mean Area Median Diameter Median Area Porosity Area Weighted Diameter 90th percentile Diameter I calculated the theoretical water permeability for each sample we’ve used and compared that to the experimental permeability using these statistics…