As we make larger and larger pores, we see that they are becoming more convoluted and have stopped looking like circles or ellipse. In order to try describing these shapes, they were given a “roundness” number which was calculated by…
Author: Karl Smith
Karl is the 'separations czar' for NRG. As a Biophysics Ph.D. Candidate, Karl has the responsibility of characterizing new membranes, modeling the unique physics of nanomembrane separations, and finding ways to apply pnc-Si technology to protein purification, nanofluidic transistors, and human hemodialysis. Karl graduated from Allegheny College in 2011 with a double major in English and Physics.
Neither Centrifugation, Sonication, nor Filtration Fix the Aggregation in the Barcikowski Lab Samples
In early May, the Barcikowski lab shipped us four samples of gold nanoparticles for us to run separations on. They took forever to get here, and had aggregated and precipitated by the time they arrived. About a week ago, the…
High salt concentrations (~50mM) shouldn't be used to tune effective pore sizes for gold colloid separations
What we’d like to have accompany the Sepcon filters is a general way to tune the pore sizes for any given separation. If, for instance, someone wanted to have a filter cutoff of 12nm, we could create a custom wafer…
Barcikowski separations
The samples of nanoparticles from the Barcikowski lab finally arrived after 9 days in transport. Regrettably, the ice pack they shipped with was completely dead, and it is possible that the samples were in some way ruined. After we received…
Posted in NRG
The Effect of Pressure on the Sieving Coefficient of a 20nm membrane with 10nm gold
It was speculated that the rate of diffusion through a charged membrane had a direct relationship with pressure – as pressure increases, the kinetic energy of the charged particles is more likely to overcome the electrostatic repulsion of the membrane,…
Posted in NRG
Barcikowski Collaboration Update
Over the last week or so I’ve taken some lovely SEM pictures with Joe, used the light scatter, and ran some separations on filters I assembled myself. Someone from the Barcikowski lab, Dr. Rehbock, got in touch with me and…
Posted in NRG
Barcikowski Collaboration Rotation Project
As a rotation student from the Biophysics depart, I’ll be spending the next six weeks or so helping Dr. Stephan Barcikowski use the nanomembranes to do a number of separations as part of a nanofabrication procedure. Dr. Barcikowski makes extremely…
