Recently, SiMPore has been exploring alternate ways for depositing our film stack.  We’ve finished our initial testing of a plasma-enhanced chemical vapor deposited film by Rogue Valley (OR), and it appears that the pore formation process is inhibited with the standard 1000 C RTP 100 C/s anneal. The most striking difference (besides the difference in…

I asked Tom to add gold PES separations of NPs to his earlier figure and to evaluate the loss of NPs during the use of these filters compared to pnc-Si. Here is what he came up  … All experiments (including pnc-Si) were done at 10 PSI with 200 ul of starting material above the membrane…

This device was built similar to the device featured in the Burns(Zydney) 2000 J. Mem. Sci. paper.  Our device seals in a SepCon formatted pnc-Si chip and allows 2 electrodes to be positioned by the chip.  A feed line pressurizes the chip with saline, and the generated potential can be measured using the electrodes.  The…

In preparation for Tuesdays meeting Jim asked me to prepare this chart to compare the results of the treated and untreated diffusion experiments from this summer. The chart values given are the percent concentration of the sample filtrate in comparison to the original “feed” solution. For instance in all of my experiments the initial “feed”…

In the previous post it seems that the membrane pores do not significantly retard proteins and that the separation characteristics are due more to the slower diffusion coefficients of the proteins.  However, in certain circumstances, the membrane may provide more of an effect.  All of these experiments and simulations took place in a relatively large…

The goal of my rotation was to create a small, self-contained electroosmosis device that operates on a microliter scale using TEM membranes.  Development of this device went through several phases, picking up where Mark Lifson left off.  One important aspect of my design is that it is put together in stages.  This allows for observation…

I made a post yesterday showing that in 20mM HEPES, pH7.5, +10mM NaCl solution equivalent amounts of DDM were diffusing through the “treated” and “untreated” SC256 samples. Additionally it appeared that minimal amounts of BSA were diffusing across either sample. I set up another diffusion experiment and let it sit overnight. DDM analysis: As observed…

I took some force curves a while ago to see if there was any difference between wrinkled and taut membranes.  Here, I present only the data with a 15nm ‘trigger’.  The trigger is a user-defined parameter that sets the maximum deflection of the cantilever during a force curve acquisition. THe y-axis in these graphs is…

Tweaking simulation was not bringing it any closer to the experimental shown in the last post.  This led me to try the experimental once more.  I set up the same system and used 1:2 dilution of the standard protein mixture.  I then homogenized the retentate and filtrate and ran 10 ul of each on a…

Yesterday I posted the results from an experiment testing diffusion of BSA and DDM with salts (10mM) across “treated” and “untreated” SC256 samples. The results posted yesterday showed relatively equal amounts of DDM diffusion in both the “treated” and “untreated” case. For the BSA diffusion however the results showed that a greater amount of BSA…