Our new diffusion chamber is finally here. Take a look at the photos first – in our next group meeting you can see the real thing. Today I will test its usability and reliability. Please keep in mind this is only the prototype, there must be upside space for improvement.
I’ve been going to considerable lengths to try and get reproducible zetapotential measurements from my streaming potential device. Zetapotential measurements are the closest we can experimentally get to measuring the surface charge of a membrane, and are important for three reasons. First, I need accurate surface charge data for the membranes if my electrostatic model is…
We have suspected that those non-open pores in the TEM image of pnc-Si are pits in the silicon membrane for a long time. Last week, I SEMed a sample, oxide (30nm)/Si(25nm)/oxide(30nm) annealed at 800C for 1min, to verify the pits features. The first figure is a TEM image which the majority feature looks like non-open…
In this post I will describe the use of the 3-D computational diffusion model as applied to separations with thick membranes. Experimental: Track etched membranes were trimmed to fit into round plastic sepcons and were sealed in the traditional way using an o-ring. 20uL of protein sample was pipetted inside the sepcon and 20uL of…
This post is a continuation of the work in Partial Etch RIE Blows out NPN Pores and MgF2 Nanomembrane Fabrication on partially etched NPN substrates. We believe the underlying NPN template influences the shape of our SERS active nanostructures and therefore the SERS properties. In this post, we’ll take a look at some of the structures resulting…
In the soon to be submitted paper on diffusion models, we list two contributions to membrane resistance. The first is due to the steric and frictional hindrance a molecule encounters as it enters and diffuses through a pore (Renkin, Deen). The second is due to the time that it takes for the molecule to diffuse…
There is strong evidence that the recent pinhole breakout is due to copper contamination in our process. I have attached two image – An SEM showing a cuprous creature eating one of our membranes and an EDX (Energy Dispersive X-ray?) spectra identifying it as a copper-rich silicide. This would also explain Dave’s TEM image of…