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20:38
AC Electrokinetic Phenomena Generated by Microelectrode Structures
Published on: July 28, 2008
ELECTROKINETIC PHENOMENA. II : THE FACTOR OF PROPORTIONALITY FOR CATAPHORETIC AND ELECTROENDOSMOTIC MOBILITIES
1Department of Physical Chemistry in the Laboratories of Physiology, Harvard Medical School, Boston.
The Journal of General Physiology
|October 30, 2009
Summary
This study compares electroendosmotic velocity to electric mobility, finding particle mobility is independent of size and shape when surface composition is identical. These findings support existing theories on particle electrophoresis.
Area of Science:
- Physical Chemistry
- Colloid Science
Background:
- Two theories predict different ratios for electroendosmotic velocity (V(E)) to particle electric mobility (V(p)).
- Previous data for glass surfaces showed discrepancies, suggesting glass is unsuitable for such investigations.
Purpose of the Study:
- To evaluate theories predicting the V(E)/V(p) ratio.
- To determine the V(E)/V(p) ratio for surfaces and particles covered by identical proteins.
- To investigate the influence of particle size and shape on cataphoretic mobility.
Main Methods:
- Re-calculation of existing data from van der Grinten for glass surfaces.
- Experimental determination of the V(E)/V(p) ratio for protein-coated flat surfaces.
- Micro-cataphoresis cell utilized to test the theory for round surfaces.
Main Results:
- Re-calculated data for glass surfaces yielded a V(E)/V(p) ratio between 2.1 and 2.8, aligning with Abramson's findings.
- For surfaces and particles coated with the same proteins, the V(E)/V(p) ratio was determined.
- For round surfaces, the V(E)/V(p) ratio was found to be approximately 1.00.
Conclusions:
- The study supports theories where cataphoretic mobility is independent of particle size and shape.
- Identical surface constitution is crucial for consistent cataphoretic mobility measurements.
- Glass is not an ideal material for investigating electroendosmotic and electrophoretic phenomena.
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