Dynamic interfacial effect of electroosmotic slip flow with a moving capillary front in hydrophobic circular microchannels.
Miniaturization of chemical analysis using microfabrication is an emerging technology. The use of polymeric materials as opposed to conventional glass substrate is also a promising alternative. As most polymeric materials are hydrophobic relative to glass, we describe here the implication for the loading process of electroosmotic flow (EOF) when a three-phase (solid-liquid-vapor) contact line exists. The presence of these interfaces can result in a large Laplace pressure that resists EOF and hence hinders its flow performance. This effect depends on the phenomenological contact angle at the solid-liquid interface. In our model for EOF, we considered simultaneously the presence of an electric double layer, liquid slips via a weaker solid-liquid interaction and Laplace pressure across a liquid-vapor interface.
Yang
Jun
J
Nanoscale Technology and Engineering Laboratory, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8, Canada.
Lu
Fuzhi
F
Kwok
Daniel Y
DY
D004574:Electromagnetic Fields; D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D009995:Osmosis; D044367:Phase Transition; D012212:Rheology