Electrostatics surface charge

Antistatic Dissipate electrostatic surface charge on polymer Quaternary ammonium compounds, long-chain... 

Membranes are used for a wide variety of separations. A membrane serves as a barrier to some particles while allowing others to selectively pass through. The membrane pore size, shape, and electrostatic surface charge are fundamental to particle removal. Reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF) relate to separation of ions, macromolecules and particles in the 0.001-10 pm range. 

Fitts, J.P. et al.. Electrostatic surface charge at aqueous/a-AljOj single crystal interfaces as probed by optical second-harmonic generation, J. Phys. Chem. 11.. 109, 7981, 2005. 

Antistatic agents Dissipate electrostatic surface charge on polymer surfaces Quaternary ammonium compounds, long-chain derivatives of glycols and polyhydric compounds, Atmos 150, lVdV-bis-(2-hydroxy-ethyl) alkyl-amine... 

From the equality of the two oppositely charged surface species, go = soHj one would conclude that the net electrostatic surface charge would be zero since the monoprotonated surface sites, 0goH> contribute no electrostatic charge. The point of electroneutrality for any S-MO interface is the isoelectric point (lEP) or zero point of charge (ZPC), which occurs at pH = 6.0 for the data in Fig. 3. 

The lack of explicit pH dependence in adsorption equations derived from the GP model was an obvious deficiency. Among other things that changing solution pH does to a S-MO interface is change the electrostatic surface charge. The apparent conclusion drawn from these facts was that the pH dependence in adsorption was due to electrostatic interaction between solute and interface since the electrostatic... 

Between the two semi-infinite phases lies a Stem layer which contains continuum solvent with dielectric strength E, surface site ions, and adsorbed solute ions. The thickness of the Stem layer, Ug, corresponds to the diameter, a, of a single surface site ion, S . The surface site ions may or may not be bound to solute ions. The presence of adsorbed solute ions will not affect Ug, but will change the valence of the surface site. In general, the area of a surface site ion, A, will be > a. This relationship can be seen qualitatively in Fig. 2 and understood quantitatively when one consideres flrat ionic diameters are nominally 2— 3 A, while surface sites are nominally spaced 7—10 A (the electrostatic surface charge density on a fully ionized surface is of the order of 0.3 coulombs m [32], which corresponds to an electrostatic surface site density of50—100 A per surface site). The volume of a surface site not occupied by a surface site ion is filled with continuum solvent. The surface... 

At real solution—solid interfaces, particularly at solution— metal oxide (S— MO) interfaces, surface site ionization and solute ion adsorption will occur, creating a permanent electrostatic surface charge, in general. Rigorous determination of an explicit equation for the adsorption-induced electrostatic surface potential,, on a surface ion in a real interface would be a very complicated problem in electrostat-... 

FIG. 14 Role of the mean electrostatic surface charge, s on the activity coefficient of anion and cation complexed surface sites. 

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