Polyelectrolytes model

Hard-sphere or cylinder models (Avena et al., 1999 Benedetti et al., 1996 Carballeira et al., 1999 De Wit et al., 1993), permeable Donnan gel phases (Ephraim et al., 1986 Marinsky and Ephraim, 1986), and branched (Klein Wolterink et al., 1999) or linear (Gosh and Schnitzer, 1980) polyelectrolyte models were proposed for NOM. Here the various models must be differentiated in detail—that is, impermeable hard spheres, semipermeable spherical colloids (Marinsky and Ephraim, 1986 Kinniburgh et al., 1996), or fully permeable electrolytes. The latest new model applied to NOM (Duval et al., 2005) incorporates an electrokinetic component that allows a soft particle to include a hard (impermeable) core and a permeable diffuse polyelectrolyte layer. This model is the most appropriate for humic substances. 

Much confusion had arisen from the polyelectrolyte-like viscosity of ionic polysoaps at low concentrations. Based on the old polyelectrolyte model of coil-to-rod transition [339-342], it was suggested that the strong increase of reduced viscosities at low concentrations would indicate a transition of intramolecularly aggregated coils to extended conformations of the polysoaps which are no more aggregated. This would mean that the polysoap characteristics would be suspended at low concentrations [126, 229, 292]. 

Figure 5. Theoretical models of DNA (a) elastic-rod model (b) hehx-coil model (c) polyelectrolyte model.

Figure 13.3 Visualisation of the water-filled channels in polyelectrolyte model for Nafion, as simulated by Elliott and Hanna [41]. The atomic fragments have been deleted for clarity, replaced by three-dimensional Connolly surfaces produced from models containing (a) 6.3% and (b) 15.9% water by mass. In the original paper, the surfaces were coloured by proximity to polar and non-polar regions.

SOLVENT EFFECT ON CHARGED POLYSACCHARIDES AND THE POLYELECTROLYTE MODEL... 

Figure 12.2.14. The rigid chain (a), the corresponding polyelectrolyte model (b) and the realistic flexible model of...

Figure 9.4 Self-oscillations induced in the polyelectrolyte model for the (BS reaction-responsive gel) system, (a) full lines limits of bistability in a neutral gel for almost equivalent chemical conditions. Gray region domain of reference sizes / o that gives rise to self-oscillations with the (black)...

Korolev, N., Lyubartsev, A. P., 8c Nordenskiold, L. (2002). Application of the Poisson Boltzmann polyelectrolyte model for analysis of equilibria between single-, double-, and triple-stranded polynucleotides in the presence of K+, Na+, and Mg2+ ions. Journal of Biomolecular Structure and Dynamics, 20, 275. 

Baeurle, S., Chariot, M., Nogovitsin, E. Grand canonical investigations of prototypical polyelectrolyte models beyond the mean field level of approximation. Phys. Rev. E 75, 011804 (2007). doi 10.1103/PhysRevE.75.011804... 

Baeurle SA, Chariot M, Nogovitsm EA (2007) Grand canonical investigatirais of prototypi cal polyelectrolyte models beyond the mean field level of approximatirai. Phys Rev E 75 011804 1 011804 11... 

SC/PRISM theory has also been applied to solutions of polyelectrolytes modeled as rigid rods [138,139]. Here, SC/PRISM accurately reproduces the long-range... 

The simplest polyelectrolyte model of biological relevance is that of a single semiinfinite impenetrable charged plane in equilibrium with a bulk electrolyte solution of known composition. The charged plane also serves as an introduction to the properties of the electric double layer. We simplify the representation of a membrane by assuming that (1) the membrane is impenetrable to ions, (2) the surface charge is uniformly distributed and constant, (3) the electrolyte is modeled as hard-sphere ions of specific size, and (4) the solvent is a structureless continuum described by a uniform dielectric coefficient... 

J. C. Gil Montoro and J. L. F. Abascal, Molec. Phys., 89, 1071 (1996). Discrete Charge Effects on the Structure of Ions around Polyelectrolyte Models. 

A. V. Lukashin, D. B. Beglov, and M. D. Frank-Kamenetskii,/. Biomolec. Struct. Dynam., 9, 517 (1991). Allowance for Spatial Dispersion of Dielectric Permittivity in Polyelectrolyte Model of DNA. 

Formulation (36) is most suitable since self-diffusion coefficients of small ions may be directly evaluated in terms of molecular parameters, for many polyelectrolyte models. Before this point is illustrated some attention should be drawn to the criterion which permits an assessment of the validity of the friction model in the present case. 

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