Surface dissociation constant

Three quantities are defined for convenience. (i) A surface dissociation constant is defined for the reaction ... 

Akiatopulu, K.Ch., Vordonis, L., and Lycomghiotis, A., Effect of lemperalure on the point of zero charge and surface dissociation constants of aqueous suspensions of y ALOj, 7. Chem. Soc. Faraday Trans. 1, 82, 3697, 1986. 

Theoretical and structural studies have been briefly reviewed as late as 1979 (79AHC(25)147) (discussed were the aromaticity, basicity, thermodynamic properties, molecular dimensions and tautomeric properties ) and also in the early 1960s (63ahC(2)365, 62hC(17)1, p. 117). Significant new data have not been added but refinements in the data have been recorded. Tables on electron density, density, refractive indexes, molar refractivity, surface data and dissociation constants of isoxazole and its derivatives have been compiled (62HC(17)l,p. 177). Short reviews on all aspects of the physical properties as applied to isoxazoles have appeared in the series Physical Methods in Heterocyclic Chemistry (1963-1976, vols. 1-6). 

This potential reflects itself in the titration curves of weak polyacids such as poly(acrylic acid) and poly(methacrylic acid) [32]. Apparent dissociation constants of such polyacids change with the dissociation degree of the polyacid because the work to remove a proton from the acid site into the bulk water phase depends on the surface potential of the polyelectrolyte. 

Surface plasmon resonance (SPR) Interaction strength (molar dissociation constant, K ). One member of the reacting pair needs to be immobilised onto an inert surface. Not suitable for selfassociation analysis. [7]... 

The apparent dissociation constant pK is strongly dependent on the electrical potential on the surface of the macroion, according to the well known equation [11]... 

Using these equations, Lowe and Walmsley [48] have calculated the dissociation constants for sugar binding at the extracellular surface of the membrane (K s = b a in Fig. 2) and at the cytoplasmic surface (K. = elf = bid) x [dgich]) from the estimated rate constants for carrier re-orientation and the measured Michaelis constants. The dissociation constant for binding at the extracellular surface of the membrane, calculated in this way, is approximately lOmM and is largely unaffec-... 

As seen in equations (32)-(34), the forward adsorptive flux depends upon the concentration of free cell surface carriers. Unfortunately, there is only limited information in the literature on determinations of carrier concentrations for the uptake of trace metals. In principle, graphical and numerical methods can be used to determine carrier numbers and the equilibrium constant, As, corresponding to the formation of M — Rcen following measurement of [M] and (M —Rceii. For example, a (Scatchard) plot of (M — RCeii /[M] versus (M — RCeii should yield a straight line with a slope equal to the reciprocal of the dissociation constant and abscissa-intercept equal to the total carrier numbers (e.g. [186]). 

Using this screening approach, a fourfold amplification of the designed library member A-P was observed. Interestingly, a fivefold amplification of the peptidic dimer P-P was also observed. Amplification factors correlated well with dissociation constants (K ) subsequently measured by surface plasmon resonance (SPR) A-P was found to have a of 30 [tM, while the more strongly amplified P-P was found to have a of 22.5 [tM. 

Eq. 1 log kD, dissociation constant V, solvent-accessible surface molecular volume (A3) gH, greatest population in highest occupied molecular orbital for methyl group hydrogen atoms. 

The magnitude of the electrostatic potential at the silica surface is, as expected from the law of mass action, pH-dependent. The variation in surface (or zeta) potential with pH must therefore be dependent on the dissociation constant of the surface silanol (Si-OH) group. 

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