Drag reduction in electro-osmosis of polymer solutions

Feng Ming Chang, Heng Kwong Tsao

Research output: Contribution to journalArticlepeer-review

23 Scopus citations

Abstract

Electro-osmosis is the preferred transport mechanism in microfluidic systems. Drag reduction in electro-osmosis of polymer solutions is observed due to polymer depletion in the electric double layer (EDL). The well-known Helmholtz-Smoluchowski (HS) equation indicates that the electro-osmosis mobility is inversely proportional to the solution viscosity. For low molecular weight the polymer size (R) is smaller than the EDL thickness (λ) and the HS equation is valid. For high molecular weight (Rλ) the chains in the EDL are partially sheared and the effective viscosity is smaller than the solution viscosity. Salt addition reduces λ and can enhance drag reduction substantially.

Original languageEnglish
Article number194105
JournalApplied Physics Letters
Volume90
Issue number19
DOIs
StatePublished - 2007

Fingerprint

Dive into the research topics of 'Drag reduction in electro-osmosis of polymer solutions'. Together they form a unique fingerprint.

Cite this