Since the last post we have been working on obtaining replicates with wafer 101 chips. The goal was to show salt dependent filtration changes. These chips were different from the ones originally used in that the pores were much smaller (7-15nm diameter) and did not exhibit any merging. It was suggested that we perform an…
The retrial on cellulose (100kD) gold separations gave similar results to the first study (results from Tecan scans): particle salt results 5 0mM no au in filtrate, retentate concentration 15 0mM no au in filtrate 5 10mM no au in filtrate, retentate concentration 15 10mM no au in filtrate I took the membranes and rinsed…
Inspired by JP’s work with the Veeco Wyko, I attempted to fit pressure-displacement curves with the equation for thin film deformation (Vlassak and Nix 1992) for two membrane geometries: 100um x 100um and 1000um x 1000um. The relationship between displacement and pressure is: P = pressure, d = displacement, C1 and C2 are geometric coefficients,…
This is just a little update on the results of the pnc-Si, cellulose, and pes separations. When I added up the retentate and filtrate, it didn’t always equal the intensity of the starting sample (keeping in mind that I was unable to collect filtrate from PES and should re-try that separation). I took the percent…
Can viscosity be determined by dynamic light scattering? Dynamic light scattering in essence measures the diffusion of particles and calculates the hydrodynamic radius using the Stokes-Einstein relation, D = kT/(6πηr). To find a size using dynamic light scattering, you need to input the viscosity so it can perform the calculation. If we don’t give the…
We got a bunch of extremely nice EO wafers through the pipeline, and I’ve been trying to do some experiments with them. There’s very few pinholes on these wafers, and the pores are beautiful. My experiments so far have been w/ SC 166. Pore image: Contributed area distribution: We need the following figures for our…
To supplement the work that Dave’s been doing with carbonization, I’m doing some chemical stability/discoloration tests. The first step of these tests is to measure the contact angles. The following are images of contact angle tests and quantitative data from ImageJ of the angles. These are SC141 chips and they are not rinsed or treated…
After seeing a reduction of pore size at 750 C, I decided to run three different soak times at a fixed acetylene concentration of 1 LPM. As expected, the longer soak time resulted in more occlusion. It seems that the carbon growth is almost linear: 5 min treatment shrinks the pores by 5 nm and…
Dave deposited a series of wafers last week at different temperatures. SC 166 -SC 173 were deposited between RT and 300C. These wafers had Jess’ E.O mask pattern ( circular sepcon) with single , 3,6 and 9 squares. The wafers were mostly pinhole free.In order to determine if deposition temperature affected the nature/ strength of…
I set up separations with 100kD cutoff Microcon (cellulose) membranes and protein standards. Here are the results: Due to shorter than normal gel, the myosin didn’t get resolved. However we can see a separation that appears to be fairly sharp. We have seen this in the past with cellulose. The different salt concentrations don’t appear…