The influence of nearest- and next-nearest-neighbor interactions on the potentiometric titration of linear poly(ethylenimine)

Smits, R. G.; Koper, Ger J. M.; Mandel, M.

doi:10.1021/j100123a047

Cited by 133 publications

(180 citation statements)

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“…3b, we have also compared the resulting titration curve with the linear nearest-neighbor Ising model (15)(16)(17)(18)(19)(20)(21). This simple model reproduces the Monte Carlo results reasonably well.…”

Section: Monte Carlo Simulationsmentioning

confidence: 70%

“…3b). Various linear polyelectrolytes with closely spaced ionizable groups behave in this fashion, for example, poly(maleic acid), poly(fumaric acid) poly(vinylamine) or poly(ethyleneimine) (14)(15)(16). For linear polyelectrolytes, at intergroup distances somewhere below 1 nm, effects of interactions become observable.…”

Section: Comparison With Experimentsmentioning

confidence: 99%

“…For planar interfaces such behavior has been documented for cationic and anionic monolayers at the air-water interface, and surfaces of latex or metal oxide particles (7)(8)(9)(10)(11)(12)(13). The corresponding data for linear polyelectrolytes include polymaleic acid, polyfumaric acid, poly(vinyl)amine, or poly(ethylene)-imine (14)(15)(16).…”

mentioning

confidence: 95%

“…In this model, one assigns to each site a two-valued state variable, which indicates whether the site is protonated or not. Thermal averages over all states are weighted by an interaction energy, which is assumed to be dominated by nearest-neighbor repulsive (antiferromagnetic) pair interactions (15)(16)(17)(18)(19)(20). Indeed, this model implies the stabilization of an intermediate state of alternating protonated and deprotonated groups, which leads to an intermediate plateau in the titration curve.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On the difference in ionization properties between planar interfaces and linear polyelectrolytes

Borkovec

Daicic

Koper

1997

Proc. Natl. Acad. Sci. U.S.A.

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Ionizable planar interfaces and linear polyelectrolytes show markedly different proton-binding behavior. Planar interfaces protonate in a single broad step, whereas polyelectrolytes mostly undergo a two-step protonation. Such contrasting behavior is explained using a discrete-charge Ising model. This model is based on an approximation of the ionizable groups by point charges that are treated within a linearized Poisson-Boltzmann approximation. The underlying reason as to why planar interfaces exhibit mean-field-like behavior, whereas linear polyelectrolytes usually do not, is related to the range of the site-site interaction potential. For a planar interface, this interaction potential is much more long ranged if compared with that of the cylindrical geometry as appropriate to a linear polyelectrolyte. The model results are in semi-quantitative agreement with experimental data for fatty-acid monolayers, water-oxide interfaces, and various linear polyelectrolytes.Ionization of proteins, weak polyelectrolytes, or water-solid interfaces is a central theme across many disciplines. The understanding of such polyprotic systems is crucial for the assessment of various important processes, such as buffering of protons and metal ions, protein-folding mechanisms, antigenantibody interactions, formation of surfactant aggregates, particle coagulation dynamics, and crystal growth. Based on the seminal work of Tanford and Kirkwood (1, 2), much progress has been made in the development of quantitative models for the dissociation of ionizable residues in proteins. The electrostatic interactions between charged residues are treated using a Poisson-Boltzmann (or other) approximation, which provides the basis for the evaluation of the thermal statistics of protonation equilibria (3-6). Because the results of such models sensitively depend on the primary, secondary, and tertiary protein structure, the derived protonation patterns appear to be rather protein-specific. The main reasons for this behavior are the heterogeneities introduced by the different proton affinities of different amino acid residues and the specific effects due to geometrical arrangement of the ionizable groups. Any generic features in the ionization process of polyprotic protein systems are difficult to recognize.Generic features in the ionization patterns can be recognized, however, for simpler polyprotic systems such as planar ionizable interfaces and weak linear polyelectrolytes, which will be the focus of this paper. Such systems may involve a high degree of homogeneity due to the presence of identical ionizable groups and simpler geometrical structure. Moreover, such systems often contain a large number of ionizable sites, so that it is sufficient to consider the limit of an infinite number of sites. The detailed description of the ionization process for planar interfaces and linear polyelectrolytes represents an essential step in the understanding of ionization of complex polyprotic systems; a development that is not only of relevance to biochemis...

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Section: Monte Carlo Simulationsmentioning

confidence: 70%

Section: Comparison With Experimentsmentioning

confidence: 99%

mentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the difference in ionization properties between planar interfaces and linear polyelectrolytes

Borkovec

Daicic

Koper

1997

Proc. Natl. Acad. Sci. U.S.A.

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“…One of the most widely used polycations is polyethylenimine (PEI). PEI contains low pKa amines, which can protonate in response to the endosomal acidic pH of ~5.5 (51). This amine protonation is hypothesized to induce the influx of protons and chloride ions into the endosomal compartment, resulting in increased osmotic pressure and ultimately endosome disruption.…”

Section: Polymer Design For Endosomal Escapementioning

confidence: 99%

Smart polymeric nanocarriers for small nucleic acid delivery

Miyata

2016

DD&T

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Ising models and acid‐base properties of weak polyelectrolytes

Borkovec

Koper

1996

Ber Bunsenges Phys Chem

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Ionization equilibria of weak polyelectrolytes and their oligomeric analogs are discussed in terms of the Ising model. Within the Ising model one treats the thermal statistics of a collection of interacting sites, which can be either protonated or deprotonated. The basic parameters of the model are microscopic pK values of individual groups and various interaction parameters between pairs and possibly triplets of sites. By performing the appropriate thermal average, one can obtain the titration curve of the system considered. For systems with finite number of ionizable sites, we recover the classical description in terms of successive protonation equilibria. Thereby one can express the ionization constants in terms of the interaction parameters. For system with infinite number of sites, such as linear polyelectrolytes, the titration curves can be also calculated explicitly. We discuss three illustrative examples in more detail: (i) a simple model for linear, weak polyelectrolytes; (ii) a refined model for same type of system which describes poly(ethylene imine) and its oligomeric analogs quantitatively; (iii) simple mean‐filed model for polymeric interfaces, such as the surface carboxylated latex particles.

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The influence of nearest- and next-nearest-neighbor interactions on the potentiometric titration of linear poly(ethylenimine)

Cited by 133 publications

References 4 publications

On the difference in ionization properties between planar interfaces and linear polyelectrolytes

On the difference in ionization properties between planar interfaces and linear polyelectrolytes

Smart polymeric nanocarriers for small nucleic acid delivery

Ising models and acid‐base properties of weak polyelectrolytes

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