Ambient pressure effects on the electrokinetic potential of Zeonor-water interfaces |
| |
Authors: | Tandon Vishal Kirby Brian J |
| |
Institution: | Department of Biomedical Engineering, Cornell University, United States. |
| |
Abstract: | Using phase-sensitive streaming potential experiments in a vacuum chamber, we demonstrate that lowering the ambient pressure of the air surrounding a hydrophobic, Zeonor microfluidic substrate results in a decrease in the time scale required for equilibration of the electrokinetic potential. At ambient air pressures below 0.74 atm, the electrokinetic potential changes from ~-84 mV to ~-11 mV in 5 h, while the same decrease occurs in a period of over 200 h when the system is at 1 atm. Returning a sub-atmospheric system (where the electrokinetic potential had equilibrated to -11 mV) to atmospheric pressure did not result in any additional change in the electrokinetic potential. This can be described as a type of hysteresis of the electrokinetic potential with dissolved gas concentration. No time or pressure dependence was observed for the electrokinetic potential of hydrophilic (silica) substrates. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|