I tested all the microbeads that the Gaborski and Lapizco-Encinas labs own. The results are summarized below. The sizes ranged from 50 nm to 2 µm. I mixed them to concentrations of 0.2 g/L for all bead less than 1 µm and 1.0 g/L for all 1 µm or greater. Interestingly, the scans look rather poor for all the samples at 1 µm or larger. I plan to repeat a couple at higher concentration to see if this helps.
Hello everyone, this post is a summary/recap of the MRS Spring meeting that was held in Phoenix, Arizona this past week (April 17 – 21). Here is an overview of two sessions: Molecular and colloidal plasmonics – Synthesis and applications (ED14) Jennifer S. Shumaker-Parry, Associate Professor at University of Utah (http://shumaker.chem.utah.edu/) Combined top-down/bottom-up for the fabrication…
I recently received wafer 567 from Dave for cell culture work. It has many intact membranes but is riddled with pinholes, having only 3 pinhole-free samples. I decided to test them for air permeability and burst pressure, shown below. I also noticed some odd features on the membrane and surrounding Si. They are circular but…
Having finished the hydraulic permeability testing with DI water I wanted to see what the effect of an introduction of protein would have on the permeability values. To do this I simply reran a set of fresh membranes at 21.63psi using a 1mg/mL solution of bovine albumin in PBS instead of water.The group on the…
We’ve calculated our instantaneous clearance numbers for the benchtop studies that use sepcon chips. Even calculating per unit area, our chips are not clearing much volume in these experiments. I believe this is due to the very low flow rate (1 µL/min). Kayli is starting experiments to use higher flow rates with the same chips…
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 minutes. 2. Assemble streaming potential device: Electrodes are inserted into silicone chord o-rings and chamber…
We’ve been moving to a new format for chips, trying to standardize an active area that has good yield and allows fluidic access through the chip itself. The SEPCON outer dimensions have been reused (5.4 mm x 5.4 mm). It’s a 1.5 mm^2 single slot chip area (2 mm x 0.7 mm) with vias that…
