- Electro-osmosis
In
electrochemistry ,physics andvascular plant biology, electro-osmosis, also called electroendosmosis, is the motion of polarliquid through a membrane or other porous structure (generally, along charged surfaces of any shape and also through non-macroporous materials which have ionic sites and allow for water uptake, the latter sometimes referred to as "chemical porosity" ) under the influence of an appliedelectric field . Electro-osmosis was first described by F.F. Reuss in1809 , and has growing applications inmicrofluidics .Applications
Vascular plant biology
In vascular plant biology, electro-osmosis is also used as an alternative or supplemental explanation for the movement of polar liquids via the
phloem that differs from thecohesion-tension theory supplied in the mass flow hypothesis and others, such ascytoplasmic streaming . [Clegg, C.J., Mackean, D. G. (2006), p340-343] Principally,companion cells are involved in the "cyclic" withdrawal of ions () from sieve tubes, and their secretion parallel to their position of withdrawal between sieve plates, resulting in polarisation of sieve plate elements alongsidepotential difference in pressure, and results in polar water molecules and other solutes present being moved upwards through the phloem. [Clegg, C.J., Mackean, D. G. (2006), p340-343] [V. V. Polevoi , T. E. Bilova1 and Yu. I. Shevtsov (2003)]In 2003,
St Petersburg University graduates based an experiment on the electro-osmosis hypothesis through the application of directelectric current to 10mm segments of mesocotyls of maize seedlings alongside one-year linden shoots used with normal conducting systems and without vascular bundles; electrolyte solutions present in the tissues moved towards the cathode that was in place, suggesting that electro-osmosis may play a role in solution transport through conductive plant tissues. [V. V. Polevoi, T. E. Bilova1 and Yu. I. Shevtsov (2003)]Physics
In
fuel cell s, electro-osomosis causesproton s moving through a proton exchange membrane (PEM) to drag water molecules from one side (anode ) to the other (cathode ).ee also
*
Capillary electrophoresis
*Electroosmotic flow
*Streaming current
*Zeta potential Notes
References
# V. V. Polevoi , T. E. Bilova1 and Yu. I. Shevtsov (2003) "Electroosmotic Phenomena in Plant Tissues " Biology Bulletin; Volume 30, Number 2
# Clegg, C.J., Mackean, D. G. (2006) "Advanced Biology - principles & applications" Hodder Stoughton Publhishers
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