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Electroosmosis solid-liquid interface

Electroosmosis or electroendosmosis is the bulk movement of the solvent (electrolyte solution) in the capillary caused by the zeta (0 potential at the wall/water interface of the capillary. Any solid-liquid interface is surrounded by solvent and solute constituents that are oriented differently compared to the bulk solution. Figure 17.2 illustrates a model of the wall-solution interface of the widely applied capillaries. Owing to the nature of the surface functional groups, in silica capillaries the silanol groups, the solid surface has an excess of negative... [Pg.583]

Electroosmosis refers to the movement of the liquid adjacent to a charged snrface, in contact with a polar liquid, under the influence of an electric field applied parallel to the solid-liquid interface. The bulk fluid of liquid originated by this electrokinetic process is termed electroosmotic flow. It may be prodnced either in open or in packed or in monolithic capillary columns, as well as in planar electrophoretic systems employing a variety of snpports, such as paper or hydrophilic polymers. The origin of electroosmosis is the electrical donble layer generated at the plane of share between the snrface of either the planar support or the inner wall of the capillary tube and the surronnding solntion, as a consequence of the nneven distribntion of ions within the solid/liquid interface. [Pg.157]

Electrokinetic flow covers in principle the transport of liquids (electroosmosis) and samples (electrophoresis) in respraise to an electric field. Both motions are associated with the electric double layer that is formed spraitaneously at the solid-liquid interface in which there is a net charge density. Compared to the traditional pressure-driven flow, electrokinetic flow is more suited to miniaturization due to its nearly plug-like velocity profile and much lower flow resistance. However, Joule heating is a ubiquitous phenomenon in electrokinetic flow that will affect the transport of both liquids and samples via temperature-sensitive material properties. [Pg.783]

The motion of electrically charged particles or molecules in a stationary medium under the influence of an electric field is called electrophoresis. In such transport the electric force is applied through a potential difference between electrodes. Selective use of the Lorentz force by applying a magnetic field can also induce such movement. Electrophoresis and electroosmosis are two key modalities of electrokinetic transport which are very useful in micro- and nanofluidics for a variety of applications including biomedical (bio-NEMS, etc ), fuel cell and micro total analysis systems ( x-TASs). In electroosmosis the bulk fluid moves due to the existence of a charged double layer at the solid-liquid interface. While onedimensional electrophoresis is more commonly used, two-dimensional electrophoresis may also become a useful tool for the separation of gel proteins based on isoelectric property. [Pg.588]

In foams with charged gas/liquid interfaces, as in other disperse systems, various electrokinetic phenomena are possible to occur. Such are the change in the transport numbers of ions, electroosmosis, streaming potential and surface conductivity. While these phenomena are largely studied in disperse systems with solid disperse phase, the first electrokinetic observations in foams have been reported only recently. [Pg.590]

Electroosmosis (EO) is the fluid motion induced by the movement of surface charges at the solid-hquid interface under the influence of typically low-frequency AC and DC electric fields [16]. Most wetted material surfaces will acquire fixed surface charges when coming into contact with a fluid that contains ions—either an electrolyte or a dielectric liquid with ionic impurities generated locally via reactions. By electrostatic attraction, the surface... [Pg.133]


See other pages where Electroosmosis solid-liquid interface is mentioned: [Pg.222]    [Pg.18]    [Pg.226]    [Pg.508]    [Pg.630]    [Pg.443]    [Pg.1730]    [Pg.177]    [Pg.1070]    [Pg.519]    [Pg.741]    [Pg.1606]    [Pg.2714]    [Pg.987]   
See also in sourсe #XX -- [ Pg.158 ]




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