Table of Contents
How do you calculate electroosmotic flow rate?
For example, if we apply 300 V along a 1-cm-long microchannel of r = 50 μm, the electro-osmotic velocity will be uEOF = 2.13 mm/s and the corresponding volumetric flow rate will be Q = 1 μL/min, when ε = 7.1 × 10–10 F/m, ζ0 = -0.1 V, and μ = 0.001 N s/m2.
What is electroosmotic flow of ions?
Definition. Electroosmotic flow is the bulk liquid motion that results when an externally applied electric field interacts with the net surplus of charged ions in the diffuse part of an electrical double layer.
What is electroosmotic flow and why does it occur?
Electroosmotic flow occurs because the walls of the capillary tubing carry a charge. The surface of a silica capillary contains large numbers of silanol groups (–SiOH). At a pH level greater than approximately 2 or 3, the silanol groups ionize to form negatively charged silanate ions (–SiO–).
What affects electroosmotic flow?
Factors that affect the electroosmotic flow in MEKC are: pH, surfactant concentration, additives, and polymer coatings of the capillary wall.
How does electro-osmosis work?
Electro-osmosis is the migration of water (and whatever is contained in the water) through a porous membrane resulting from a potential difference caused by the flow of electric charge through the membrane. The liquid transportation rate depends on: The properties of liquid. The properties of solid.
How does electro osmosis work?
What is the difference between electrophoretic mobility and electroosmotic flow?
Mobility is proportional to the q/r ratio (q = charge and r = solute size). Solvated cations drag water molecules during the migration, hence there is net solution movement from anode toward cathode. Electroosmotic flow results because of the electric double layer than forms near the capillary wall.
What is electro-osmotic force?
Electroosmosis is the flow of liquid that is in contact with a charged solid surface when an electric field is applied, and it becomes an important consideration with the increased surface area-to-volume ratio associated with small diameter capillaries.