Title: On the effect of surfactant adsorption and viscosity change on apparent slip in hydrophobic microchannels

Authors: Christian Kunert, Jens Harting

Addresses: Institute for Computational Physics, University of Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart, Germany. ' Institute for Computational Physics, University of Stuttgart, Pfaffenwaldring 27, D-70569 Stuttgart, Germany

Abstract: Substantial effort has been invested to understand the effect of boundary slippage in microfluidics. However, a satisfactory understanding is still lacking due to extremely precise experiments required. Here, we apply the lattice Boltzmann method to model hydrophobic microchannel flows. We find a possible explanation for experiments observing slip depending on the flow velocity – in contradiction to previous studies. We show that these observations can be explained by not fully developed flow profiles in the channel. Further, we show a decreasing slip length with increasing viscosity and demonstrate the effect of adding surfactant to fluid flow in hydrophobic microchannels.

Keywords: lattice Boltzmann method; microflows; apparent slip; surfactant adsorption; viscosity change; hydrophobic microchannels; boundary slippage; microfluidics; microchannel flow; fluid flow.

DOI: 10.1504/PCFD.2008.018090

Progress in Computational Fluid Dynamics, An International Journal, 2008 Vol.8 No.1/2/3/4, pp.197 - 205

Available online: 30 Apr 2008 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article