Interactions of neutral semipermeable shells in asymmetric electrolyte solutions

Lobaskin, Vladimir; Bogdanov, Artem N.; Vinogradova, Olga I.

doi:10.1039/c2sm25605c

Cited by 9 publications

(13 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4][5][6][7][8][9][10] In all these systems the uptake, storage, and release of active agents and cosolutes (e.g., reactants, pollutants, ligands, drugs) are decisive processes, which have to be controlled and programmed to the material. The gels in these applications often form film-like layers [11,12], shells, and membranes that modulate the permeation [13,14] and separation of the cosolutes by their wide range of controllable physicochemical behavior. A fundamental property describing the permeation and sorption of cosolutes to polymer networks on the most global level is the partitioning…”

Section: Introductionmentioning

confidence: 99%

Cosolute Partitioning in Polymer Networks: Effects of Flexibility and Volume Transitions

et al. 2017

View full text Add to dashboard Cite

We study the partitioning of cosolute particles in a thin film of a semi-flexible polymer network by a combination of coarse-grained (implicit-solvent) stochastic dynamics simulations and meanfield theory. We focus on a wide range of solvent qualities and cosolute-network interactions for selected polymer flexibilities. Our investigated ensemble (isothermal-isobaric) allows the network to undergo a volume transition from extended to collapsed state while the cosolutes can distribute in bulk and network, correspondingly. We find a rich topology of equilibrium states of the network and transitions between them, qualitatively depending on solvent quality, polymer flexibility, and cosolute-network interactions. In particular, we find a novel 'cosolute-induced' collapsed state, where strongly attractive cosolutes bridge network monomers albeit the latter interact mutually repulsive. Finally, the cosolutes' global partitioning 'landscape', computed as a function of solvent quality and cosolute-network interactions, exhibits very different topologies depending on polymer flexibility. The simulation results are supported by theoretical predictions obtained with a twocomponent mean-field approximation for the Helmholtz free energy that considers the chain elasticity and the particle interactions in terms of a virial expansion. Our findings have implications on the interpretation of transport processes and permeability in hydrogel films, as realized in filtration or macromolecular carrier systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Cosolute Partitioning in Polymer Networks: Effects of Flexibility and Volume Transitions

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Based on earlier results, 33 one can expect to observe the same qualitative picture at least at low polyion concentrations, while at the higher concentrations the correlation effects might become significant. 37 We leave the study of the latter regime for a future work.…”

Section: Potentialmentioning

confidence: 99%

“…Recent integral equation study suggested charge correlation effects in large concentration solutions of multivalent ions that could result in short-range attractions. 37 We are unaware of any previous work that has addressed the ques-tion of interaction of a semipermeable membrane with a wall.…”

Section: Introductionmentioning

confidence: 99%

Electrostatic interaction of heterogeneously charged surfaces with semipermeable membranes

2013

Self Cite

View full text Add to dashboard Cite

In this paper we study the electrostatic interaction of a heterogeneously charged wall with a neutral semipermeable membrane. The wall consists of periodic stripes, where the charge density varies in one direction. The membrane is in a contact with a bulk reservoir of an electrolyte solution and separated from the wall by a thin film of salt-free liquid. One type of ions (small counterions) permeates into the gap and gives rise to a distance-dependent membrane potential, which translates into a repulsive electrostatic disjoining pressure due to an overlap of counterion clouds in the gap. To quantify it we use two complementary approaches. First, we propose a mean-field theory based on a linearized PoissonBoltzmann equation and Fourier analysis. These calculations allow us to estimate the effect of a heterogeneous charge pattern at the wall on the induced heterogeneous membrane potential, and the value of the disjoining pressure as a function of the gap. Second, we perform Langevin dynamics simulations of the same system with explicit ions. The results of the two approaches are in good agreement with each other at low surface charge and small gap, but differ due to nonlinearity at the higher charge. These results demonstrate that a heterogeneity of the wall charge can lead to a huge reduction in the electrostatic repulsion, which could dramatically facilitate a self-assembly in complex synthetic and biological systems.

show abstract

“…The neglect of correlations among ions inherent in the mean-field approximation for Ω is valid for weakly-correlated monovalent ions, but questionable for more strongly correlated multivalent microions. [29][30][31] For this reason, we restrict our considerations to monovalent ions.…”

Section: Poisson-boltzmann Theory Of Bulk Dispersionsmentioning

confidence: 99%

“…25 These ion density differences were attributed to the capsule semipermeability and explained by a macroscopic theoretical model of Donnan equilibrium. 25,27 Vinogradova et al [29][30][31] applied Poisson-Boltzmann (PB) theory to study the osmotic pressure acting on semipermeable shells in polyion solutions. Stukan et al 28 used molecular dynamics simulation to study ion distributions near nanocapsules that are permeable to solvent and counterions, but impermeable to polyelectrolyte coils, which were modeled as soft colloids.…”

Section: Introductionmentioning

confidence: 99%

Ion density deviations in semipermeable ionic microcapsules

Tang

Denton

2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

By implementing the nonlinear Poisson-Boltzmann theory in a cell model, we theoretically investigate the influence of polyelectrolye gel permeability on ion densities and pH deviations inside the cavities of ionic microcapsules. Our calculations show that variations in permeability of a charged capsule shell cause a redistribution of ion densities within the capsule, which ultimately affects the pH deviation and Donnan potential induced by the electric field of the shell. We find that semipermeable capsules can induce larger pH deviations inside their cavities that can permeable capsules. Furthermore, with increasing capsule charge, the influence of permeability on pH deviations progressively increases. Our theory, while providing a self-consistent method for modeling the influence of permeability on fundamental properties of ionic microgels, makes predictions of practical significance for the design of microcapsules loaded with fluorescent dyes, which can serve as biosensors for diagnostic purposes.

show abstract

Interactions of neutral semipermeable shells in asymmetric electrolyte solutions

Cited by 9 publications

References 36 publications

Cosolute Partitioning in Polymer Networks: Effects of Flexibility and Volume Transitions

Cosolute Partitioning in Polymer Networks: Effects of Flexibility and Volume Transitions

Electrostatic interaction of heterogeneously charged surfaces with semipermeable membranes

Ion density deviations in semipermeable ionic microcapsules

Contact Info

Product

Resources

About