Ionic Origin of Electro-osmotic Flow Hysteresis.

ABSTRACT: Electro-osmotic flow, the driving of fluid at nano- or micro-scales with electric field, has found numerous applications, ranging from pumping to chemical and biomedical analyses in micro-devices. Electro-osmotic flow exhibits a puzzling hysteretic behavior when two fluids with different concentrations displace one another. The flow rate is faster when a higher concentration solution displaces a lower concentration one as compared to the flow in the reverse direction. Although electro-osmotic flow is a surface phenomenon, rather counter intuitively we demonstrate that electro-osmotic flow hysteresis originates from the accumulation or depletion of pH-governing minority ions in the bulk of the fluid, due to the imbalance of electric-field-induced ion flux. The pH and flow velocity are chang

SUBMITTER: Lim CY 

PROVIDER: S-EPMC4770316 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature