Abstract
We describe a technique that measures ultralow interfacial tensions using paramagnetic spheres in a co-flow microfluidic device designed with a magnetic section. Our method involves tuning the distance between the co-flowing interface and the magnet's center, and observing the behavior of the spheres as they approach the liquid-liquid interface-the particles either pass through or are trapped by the interface. Using threshold values of the magnet-to-interface distance, we make estimates of the two-fluid interfacial tension. We demonstrate the effectiveness of this technique for measuring very low interfacial tensions, O(10-6-10-5) N m-1, by testing solutions of different surfactant concentrations, and we show that our results are comparable with measurements made using a spinning drop tensiometer.
Original language | English (US) |
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Pages (from-to) | 119-125 |
Number of pages | 7 |
Journal | Lab on a Chip |
Volume | 13 |
Issue number | 1 |
DOIs | |
State | Published - Jan 7 2013 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- Bioengineering
- Biochemistry
- Biomedical Engineering