Monte Carlo study of adsorption of a polyelectrolyte onto charged surfaces

Kong, C. Y.; Muthukumar, Murugappan

doi:10.1063/1.476703

Cited by 144 publications

(147 citation statements)

References 33 publications

Supporting

Mentioning

130

Contrasting

Order By: Relevance

“…Because the charge density (τ) of PAA here is at least twice that of pectin and HA, we include AMPS-containing copolymers ("DMF20" or "DMF25") of the same (relatively low) linear charge density as pectin and HA, i.e., average spacing between charges about 12 Å. 49 The intuitive expectation that binding is diminished by polymer chain stiffness, supported by theory 26 and simulations, 27,53,54 is borne out by the results for micelle binding in Figure 7A. The prefactor in eq 6b, now seen as the slope of the Y c vs I a plots (s), increases nearly proportionally to l p o (See Figure 7, inset), although the strong binding and low slope for PAA could be due to either its higher charge density or to charge mobility discussed in the previous section.…”

Section: Resultsmentioning

confidence: 99%

“…The prefactor in eq 6b, now seen as the slope of the Y c vs I a plots (s), increases nearly proportionally to l p o (See Figure 7, inset), although the strong binding and low slope for PAA could be due to either its higher charge density or to charge mobility discussed in the previous section. Theory 26 indicates that polyelectrolyte adsorption onto spheres is promoted by a reduction in l 1, a chain stiffness parameter that is an expansion factor for the end-to-end chain length in terms of bare Kuhn length. In agreement with this theory, increased binding strength is seen with a decrease in chain stiffness for three polyelectrolytes with similar charge densities: DMF20/25, HA, and pectin.…”

Section: Resultsmentioning

confidence: 99%

“…25 In addition to σ, , and κ, theory also points to the importance of the polymer chain stiffness, usually parameterized as the bare or intrinsic persistence length l p o , and the expectation of diminished polyelectrolyte binding (larger σ c ) for large l p o is also borne out by simulations. 26,27 An additional polyelectrolyte property is charge mobility, and the ability of transient charges arising from proton migration to adapt to colloid charge patterns and so yield higher affinity has been suggested by experiment 28 and simulations. In contrast to such "annealed" polyelectrolytes, strong or "quenched" polyelectrolytes can arrive at charge complementarity only through sequence distributions arising from synthesis conditions, as suggested by Feng et al 13 The purpose of the present work is to investigate the effects on colloid binding of these polyelectrolyte structural variables: chain stiffness, charge density, charge mobility, and sequence distribution.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Polyelectrolyte Chain Stiffness, Charge Mobility, and Charge Sequences on Binding to Proteins and Micelles

et al. 2006

View full text Add to dashboard Cite

The binding affinities of polyanions for bovine serum albumin in NaCl solutions from I ) 0.01-0.6 M, were evaluated on the basis of the pH at the point of incipient binding, converting each such pH c value into a critical protein charge Z c . Analogous values of critical charge for mixed micelles were obtained as the cationic surfactant mole fraction Y c . The data were well fitted as Y c or Z c ) KI a , and values of K and a were considered as a function of normalized polymer charge densities (τ), charge mobility, and chain stiffness. Binding increased with chain flexibility and charge mobility, as expected from simulations and theory. Complex effects of τ were related to intrapolyanion repulsions within micelle-bound loops (seen in the simulations) or negative protein domainpolyanion repulsions. The linearity of Z c with I at I < 0.3 M was explained by using protein electrostatic images, showing that Z c at I < 0.3 M depends on a single positive "patch"; the appearance of multiple positive domains I > 0.3 M (lower pH c ) disrupts this simple behavior.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Polyelectrolyte Chain Stiffness, Charge Mobility, and Charge Sequences on Binding to Proteins and Micelles

et al. 2006

View full text Add to dashboard Cite

show abstract

“…The expectation then is that σ c increase with L p . Muthukumar,19,30 for example, proposed the following relationship: σ c ∼ l K R 2 at constant I, charge per polymer repeat unit (q), colloid radius (R), where l K is the bare Kuhn length (twice the bare persistence length) and R 2 is the expansion factor for the polymeric mean-square end-to-end distance. Linse and co-workers 31,32 reported that a greater number of polyelectrolyte segments would reside near a spherical macroion for polyelectrolytes of low L p in the 0-300 mM salt concentration regime.…”

Section: Introductionmentioning

confidence: 99%

Role of Polyelectrolyte Persistence Length in the Binding of Oppositely Charged Micelles, Dendrimers, and Protein to Chitosan and Poly(dimethyldiallyammonium chloride)

2005

View full text Add to dashboard Cite

The effect of polyelectrolyte chain flexibility on adsorption to oppositely charged colloidal particles and its parametrization by persistence length have been investigated by comparison of PDADMAC and chitosan, polycations of equal linear charge density but of respectively low and high bare persistence lengths, relatively. Their relative affinity to (i) nonionic/anionic mixed micelles, (ii) carboxyl-terminated dendrimers, and (iii) bovine serum albumin (BSA) was studied by turbidimetric titrations. Potentiometric titrations and dynamic light scattering experiments as well as molecular modeling with SPARTAN were used to characterize and model these systems. The experimental and modeling results lead to the conclusion that while chain stiffness does influence the binding of polyelectrolytes to oppositely charged colloids, the persistence length is not necessarily an appropriate measure of chain flexibility on short length scales.

show abstract

“…Despite significant efforts and progresses [5][6][7][8][9][10][11], the understanding of charged complexes is still unsatisfactory and lacks behind that of neutral complexes. Certain insight into the complexation process is typically obtained by approximation schemes, e.g., variational calculations [6 -9], which, however, may lead to controversial results [12] and often apply only in limiting situations such as pointlike particles [9] or large colloidal radii [6].…”

mentioning

confidence: 99%

Critical Adsorption of Polyelectrolytes onto Charged Spherical Colloids

Winkler

Cherstvy

2006

Phys. Rev. Lett.

View full text Add to dashboard Cite

The adsorption of a flexible polyelectrolyte in a salt solution onto an oppositely charged spherical surface is investigated. An analytical solution is derived, which is valid for any sphere radius and consistently recovers the result of a planar surface in the limit of large sphere radii, by substituting the Debye-Hückel potential via the Hulthén potential. Expressions for critical quantities such as the critical radius and the critical surface charge density are provide. A comparison of our theoretical results with experiments and computer simulations yields remarkable good agreement. DOI: 10.1103/PhysRevLett.96.066103 PACS numbers: 68.43.De, 82.35.Rs The complexation of charged macroions by oppositely charged polyelectrolytes is a fundamental process in biological systems and many technical applications. Particular examples are the complexation of histone proteins by DNA in nucleosomal core particles [1,2] as well as complexes of polyelectrolytes with charged colloids and micelles [3]. Industrial applications are as diverse as stabilization of colloidal suspensions, water treatment, and paper making [4].The understanding of the complexation between a polyion and a macroion surface accompanied by screening effects due to counterions and salt posses a major theoretical challenge [5]. Despite significant efforts and progresses [5][6][7][8][9][10][11], the understanding of charged complexes is still unsatisfactory and lacks behind that of neutral complexes. Certain insight into the complexation process is typically obtained by approximation schemes, e.g., variational calculations [6 -9], which, however, may lead to controversial results [12] and often apply only in limiting situations such as pointlike particles [9] or large colloidal radii [6].The theoretical studies of the adsorption behavior of polyelectrolytes onto spherical surfaces [7,10,11,13,14] lead to the observation of a phase-transition-like behavior; i.e., a bound polymer state appears at certain critical conditions which depend on, e.g., the sphere radius and screening of the Coulomb interaction. The variational calculations of Muthukumar and his co-workers [6,8] have provided useful insight into this transition in the limit of large sphere radii. Experiments on polyelectrolyte-protein and -micelle complexes [15] and computer simulations [14], however, typically yield dependencies of the critical quantities on the Debye screening length which deviate from the theoretical predictions. To understand and interpret the experimental results correctly, an analytical solution of the adsorption problem valid for any sphere radius is mandatory.In this Letter, we will present an exact solution for the critical adsorption of a flexible polyelectrolyte onto an oppositely charged spherical macroion. Expressions for critical quantities are provided, which are valid for any sphere radius. In particular, in the limit of zero macroion curvature, the results for a planar surface are obtained. In general, we find a significantly different dependence of the critica...

show abstract

Monte Carlo study of adsorption of a polyelectrolyte onto charged surfaces

Cited by 144 publications

References 33 publications

Effects of Polyelectrolyte Chain Stiffness, Charge Mobility, and Charge Sequences on Binding to Proteins and Micelles

Effects of Polyelectrolyte Chain Stiffness, Charge Mobility, and Charge Sequences on Binding to Proteins and Micelles

Role of Polyelectrolyte Persistence Length in the Binding of Oppositely Charged Micelles, Dendrimers, and Protein to Chitosan and Poly(dimethyldiallyammonium chloride)

Critical Adsorption of Polyelectrolytes onto Charged Spherical Colloids

Contact Info

Product

Resources

About