The mechanism of organic dye photobleaching is not well understood, but there are a few methods out there for reducing the rate of photobleaching.  Some literature suggests that photobleaching is due to excess oxygen in solution and the interaction between…

Membrane chips were amino-silanized with APTES in the YES system.  I performed the standard electroosmosis tests with these chips.  Here are the flow rates in comparison with non treated and oxidized membranes: Here are the calculated zeta potentials: As you…

Here is an attempt at the active area figure using the “newer” EO membranes (SC172).  Here is the raw flow data for the three membrane sizes: If we take the slopes from this figure, we get the flow rates in…

In prep for manuscript writing I came across a paper that says they’ve created a super efficient EO pump that uses extremely low voltages.  Their top flow rate (.125 mL/(min V cm2) ) is comparable to the flow rates I…

Back a year or more ago, we had analyzed the EO flow rates from pnc-Si and determined that the flow was much higher than any other material.  We then went on to try to calculate the zeta potential using the…

Ag/AgCl electrodes are used overwhelmingly in streaming potential and sometimes in electroosmosis.  The benefit of using Ag/AgCl in electroosmosis should be less gas generation and the ability to make an enclosed pump.  Here is some information on my attempt at…

All electrokinetic phenomena are connected by a form of the Helmholtz-Smoluchowski equation.  In the case of electroosmosis, the equation can be written as follows: where v is the velocity (in m/s) of water flow through the pores, epsilon the permittivity,…

I’ve tested several membrane types with the streaming potential apparatus in order to calculate zeta potential.  Here are the results: All materials in the above chart have negative zeta potentials.  Pnc-Si seems to have the highest overall potential, followed by…

In this post I will describe recent streaming potential measurements for PES membranes and the calculated apparent zeta potentials from these measurements. Setup: 1. Fabricate Ag/AgCl electrodes: Silver wire at the anode in 1M KCl at 1mA current for 20…

In the next paper that I’d like to publish, I will compare protein separations for two membranes with different pore distributions to a single membrane at two salt concentrations (basically a redo of this post).  My most recent trial with…