Adsorption of a synthetic heparinoid polyelectrolyte on an ion-exchanging surface

Froehling, Peter E.; Bantjes, D Adriaan; Kolář, Z.

doi:10.1016/0021-9797(77)90062-5

Cited by 13 publications

(4 citation statements)

References 18 publications

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“…The adsorbed polyelectrolytes form a two-dimensional adsorbed layer for fractions of charged monomers f > 0.05 for which the polymer surface excess increases with increasing salt concentration ( screening-enhanced adsorption ). The screening-reduced adsorption was also observed in other experiments on polyelectrolyte adsorption. − The screening-enhanced adsorption was reported by Kawaguchi et al for adsorption of completely quaternized poly(4-vinyl- N - n -propylpyridinium bromide) on silica, and by Bonekamp for adsorption of polylysine onto silver-iodide crystal and on glass. The linear dependence of the polymer surface excess on the square root of salt concentration (Γ ∼ ) was reported by Kawaguchi et al and by Marra et al for adsorption of polystyrene sulfonate on weakly charged silica at pH ≈ 2.…”

Section: Discussionmentioning

confidence: 54%

Adsorption of Polyelectrolytes at Oppositely Charged Surfaces

2001

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We have developed a scaling theory of polyelectrolyte adsorption at an oppositely charged surface. At low surface charge densities, we predict two-dimensional adsorbed layers with thickness determined by the balance between electrostatic attraction to the charged surface and chain entropy. At high surface charge densities, we expect a 3-dimensional layer with a density profile determined by the balance between electrostatic attraction and short-range monomer-monomer repulsion. These different stabilizing mechanisms result in a nonmonotonic dependence of the layer thickness on the surface charge density. For adsorption of polyelectrolyte chains from salt solutions, the screening of the electrostatic repulsion between adsorbed polyelectrolyte chains results in large overcompensation of the surface charge for two-dimensional adsorbed layers. At higher salt concentrations this overcompensation of the surface charge by the 2-d adsorbed layer is independent of the original surface charge and depends only on the fraction of the charged monomers on the polyelectrolyte chains and increases with ionic strength. The polyelectrolyte surface excess in 3-d adsorbed layers increases at low ionic strength and decreases at higher ionic strength.

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Section: Discussionmentioning

confidence: 54%

Adsorption of Polyelectrolytes at Oppositely Charged Surfaces

2001

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“…level were obtained, which contrasts with those from the addition of molecular halogen to glucal [156], Similarly, 2-desoxy-2-bromo-Dmannose and 2-desoxy-2-bromo-D-glucose were obtained using radiobromine and N-chlorosuccinimide or chloramine-T [254]. Chloramine-T has also been used for the formal addition of the interhalogen 125 ICI to olefinic polyelectrolytes [255,256]. In a comparative study of N-chlorosuccinimide compounds, a surprisingly small deviation of the labeling yield was found for anisóle, toluene and benzene, as shown in Table 3 [249,257].…”

Section: Direct Electrophilic Halogenationmentioning

confidence: 99%

No-Carrier-Added Radiohalogenation Methods with Heavy Halogens

1983

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Radiolabeling methods with the heavy halogens bromine, iodine and astatine are reviewed. The methods are evaluated on the basis of their underlying chemical principles and their usefulness for the no-carrier-added labeling of biologically-useful compounds. Special emphasis is placed on the stability, specific activity, and quality control of radiohalogenation products using the shortlived, neutron-deficient nuclides 7s ' 7 'Br, '"I, and 2 "At in view of their importance as radiopharmaceuticals.

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“…The opposite trend has only been accounted for in a few studies (for example, see Refs. (14,29,(31)(32)(33)(34)(35)(36)(37)). Furthermore, information on the interaction forces in this latter case is absent despite its relevance in related phenomena.…”

Section: Introductionmentioning

confidence: 98%