Study of Sample Dispersion Mechanisms in an Electroosmotically Pumped MicroChannel

摘要

This paper presents detailed simulations of electroos-motic microchannei flow to study the effect of species charge, chemical reaction and random ζ potential variability on both elektrokinetic and hydrodynamic dispersion. The physical model used accounts for the coupled nature of momentum, species transport and reactions, as well as the electrostatic field. The chemistry model accounts for pH-dependent protein labeling reactions as well as detailed buffer electrochemistry. Using poly-nomical chaos expansions, the model also accounts for stochastic ζ potential variability due to heterogeneous wall surface properties. The results show that dispersion increases for higher species charges and for larger variability in ζ. The dispersion also depends mildly on the correlation length of the ζ potential variability.