Surface potential dependence

K. Masamoto, K. Matsuura, S. Itoh, and M. Nishimura, Surface potential dependence of the distribution of charged dye molecules onto photosynthetic membranes, J. Biochem. 89, 397-405(1981). 

Figure 4.4 shows the calculated relationship between the surface potential and surface charge for different concentrations of a monovalent salt. We see that for small potentials the surface charge density is proportional to the surface potential. Depending on the salt concentration, the linear approximation (dashed) is valid till ipo 40...80 mV. At high salt concentration more surface charge is required to reach the same surface potential than for a low salt concentration. 

As with the insoluble films, the amount of the surface potential depends on the vertical component of the dipole of the molecules, and therefore on the orientation of this dipole and of the molecules to the surface. All... 

It is seen that the potential distribution and the plate surface potential depend strongly on the size of rod-like ions. 

The acid-hase characteristics of the surface groups (relative speciation of surface groups as a function of pH in upper figure) determine the pH of zero potential (point of zero proton condition MeOHt = =MeO ). The Nernst equation—a surface potential dependence on pH of (RT/Fj In 10 (= 59 mvolt at 25°C)—is not fulfilled. The lines in the lower figure were calculated from alkalimetric and acidimetric titration curves using... 

The distance-dependence of the surface potentials depends on a number of parameters such as the dielectric constant, the ionic strength, the net excess surface charge density, temperature etc. An indication of the order of magnitude and distances involved of this is shown in Figure 5.3. 

Bioelectric dipole moments range from milliampere-millimeter currents associated with the heart and skeletal muscle to nanoampere-millimeter for nerve currents. The volume-conductor relation shows that the detection of these current moments depends on a number of variables besides dieir strength. For example, surface potentials depend both on the dipole distance and on the orientation of the dipole moment with respect to the electrode. 

L. Miller, and M. R. van de Mark, A poly-p-nitrostyrene electrode surface Potential dependent conductivity and electroactive properties, J.Electroanal.Chem., 100 3223 (1978). 

Fig. 19.14 Layer-by-Layer assembly by the consecutive adsorption of cationic and animiic pillar [5]arenes. The multi-layered film showed size-selective and surface potential-dependent moleen-lar recognition properties (Reprinted with permission from ref. [53], Copyright 2015 American Chemical Society)...

A large variety of special electrodes have been developed to test for a very wide range of ions. Many involve an insoluble membrane, capable of electrical conduction, whose surface potential depends chiefly on the concentration of a particular ion. 

Fig. 1 Charge inversion for polyelectrolyte multilayers represented as the surface potential dependence on the number of adsorbed layer, N. a Charge inversion as it was obtained by the Kelvin probe for (PDADMAC + PSS) multilayers adsorbed from a NaCl solution of concentration 50 mM onto a flat surface. Adapted from Ref. [80] with permission from The Royal Society of Chemistry, b Zeta potential of (PSS + PAH)n multilayers deposited onto colloidal microparticles of methylformamide with a positive bare charge. Adapted with permission from Ref. [52]. Copyright (1998) American Chemical Society, c Zeta potential changes evaluated using Streaming potential for multilayers built with PSS and PAH, the results are represented as zeta potential against number of measurement. The number of measurements is related to the number of times that each single layer was measured and it shows as accumulative number with the increase of the layer number. Adapted with permission from Ref. [83]. Copyright (2000) American Chemical Society...

Miller LL, Van den Mark MR (1978) A poly-p-nitrostyrene electrode surface. Potential dependent conductivity and electiocatalytic properties. J Am Chem Soc 100 3223-3225... 

The value and sign of this surface potential depend on the charge of the head group and the concentration of salt. Microemulsions are optically clear, microheterogeneous fluids consisting of surfactant, solvent, and one or more additional components, usually alcohol or hydrocarbon. Oil-in-water (o/w) microemulsions have water as the bulk phase and contain aggregates... 

The MOH species which is present on the surface of the metal oxide is amphoteric in nature and has a tendency to attract both acidic and basic species. These active groups interact with either OH or groups of the analyte solution. These surface interactions lead to a protonation or deprotonation of the MOH groups and develop a surface charge which is equal to the pH of the analyte solution. The ion-sensitive CuO film thus contains surface sites which can specifically interact with H ions (hydrogenate) after interaction with an electrolyte solution. The CuO surface charge and surface potential depend on the protonation or deprotonation of these sites which is equal to the pH of electrolyte solution. 

Macroscopic Kelvin probe studies of thin PMMA films indicated that their surface potential depends on the polymer stereoregularity and molecular conformation. Furthermore, PMMA has a polar ester group -COOCH3 with dipole moment of 1.6 whereas, for example, dipole moment of the styrene... 

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