Continuum theories of structured dielectrics

Blossey, Ralf; Podgornik, Rudolf

doi:10.1209/0295-5075/ac7d0a

Cited by 4 publications

(4 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is useful to put our model in the context of earlier models for structural interactions in liquid dielectrics and results obtained from them. As we have discussed in detail in our review [12], the class of models based entirely on the polarization field has so far largely focused on the ion-free case or single solvated ions. On the other hand, there are the dipolar Poisson-Boltzmann theories built on the single order parameter of the electrostatic potential [16].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A comprehensive continuum theory of structured liquids

Blossey

Podgornik

2023

J. Phys. A: Math. Theor.

Self Cite

View full text Add to dashboard Cite

We develop a comprehensive continuum model capable of treating both electrostatic and structural interactions in liquid dielectrics. Starting from a two-order parameter description in terms of charge density and polarization, we derive a field-theoretic model generalizing previous theories. Our theory explicitly includes electrostatic and structural interactions in the bulk of the liquid and allows for polarization charges within a Drude model. In particular we provide a detailed description of the boundary conditions which include the charge regulation mechanism and surface polarization, which is explained both in general terms and analyzed for an exemplary model case. Future applications of our theory to predict and validate experimental results are outlined.

show abstract

Section: Discussionmentioning

confidence: 99%

“…In the development of this theory we were guided by the Onsager-Dupuis theory of the dielectric properties of ice [8][9][10][11]. For a recent perspective on how our work [7] can be placed in the context of earlier theories of polarization, see [12].…”

Section: Introductionmentioning

confidence: 99%

A comprehensive continuum theory of structured liquids

Blossey

Podgornik

2023

J. Phys. A: Math. Theor.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Here, we assume a soft passage across the NP boundary described by a switch function ϵ ( r ) = f sw ( R , σ , r ) = ϵ 0 + ϵ ∞ e r − R ϵ / σ 1 + e r − R ϵ / σ depending on a switching of the radius and width, R ϵ and σ. This definition exploits the space locality of the electric response, often used in biosystems, allowing one to evaluate the full dielectric response from atomistic simulations from the space distribution of the solvent or solute . Assuming that the ( r ) profile follows that of the water penetration into the NP as described by ρ wat ( r ), we fit function (eq ) on it (route (iii)).…”

Section: Methods and Theoretical Frameworkmentioning

confidence: 99%

Deconstructing Electrostatics of Functionalized Metal Nanoparticles from Molecular Dynamics Simulations

Bini,

Tozzini,

Brancolini

2023

J. Phys. Chem. B

View full text Add to dashboard Cite

Gold nanoparticles (NPs) with different surface functionalizations can selectively interact with specific proteins, allowing a wide range of possible applications in biotechnology and biomedicine. To prevent their tendency to aggregate and to modulate their interaction with charged biomolecules or substrates (e.g., for biosensing applications), they can be functionalized with charged groups, introducing a mutual interaction which can be modulated by changing the ionic strength of the solvent. In silico modeling of these systems is often addressed with low-resolution models, which must account for these effects in the, often implicit, solvent representation. Here, we present a systematic conformational dynamic characterization of ligand-coated gold nanoparticles with different sizes, charges, and functionalizations by means of atomistic molecular dynamics simulations. Based on these, we deconstruct their electrostatic properties and propose a general representation of their average-long-range interactions extendable to different sizes, charges, and ionic strengths. This study clarifies in detail the role of the different features of the NP (charge, size, structure) and of the ionic strength in determining the details of the interparticle interaction and represents the first step toward a general strategy for the parametrization of NP coarse-grained models able to account for varying ionic strengths.

show abstract

“…This model has been further refined and is frequently interpreted in terms of water-dipole orientational ordering and the nonlocal dielectric water response. − It has been noted by Ninham that the relevant water ordering could also be related to the tetrahedrality or changes in the hydrogen-bond network . In fact, the description of the electrostatic and structural interactions in polarizable liquids based on continuum theory is currently regaining significant interest. − Although such theoretical models provide conceptual insight and scaling laws for the proposed structural force, what is lacking in the literature is a quantitative comparison of the predicted water-structure profiles and indirect hydration-force magnitudes with real molecular systems. Experimentally, this is difficult because of the presence of the competing direct hydration interactions and because water-structure profiles are experimentally not available for varying surface separations.…”

Section: Introductionmentioning

confidence: 99%

Water Structuring Induces Nonuniversal Hydration Repulsion between Polar Surfaces: Quantitative Comparison between Molecular Simulations, Theory, and Experiments

Schlaich,

Daldrop,

Kowalik

et al. 2024

Langmuir

View full text Add to dashboard Cite

Polar surfaces in water typically repel each other at close separations, even if they are charge-neutral. This so-called hydration repulsion balances the van der Waals attraction and gives rise to a stable nanometric water layer between the polar surfaces. The resulting hydration water layer is crucial for the properties of concentrated suspensions of lipid membranes and hydrophilic particles in biology and technology, but its origin is unclear. It has been suggested that surface-induced molecular water structuring is responsible for the hydration repulsion, but a quantitative proof of this water-structuring hypothesis is missing. To gain an understanding of the mechanism causing hydration repulsion, we perform molecular simulations of different planar polar surfaces in water. Our simulated hydration forces between phospholipid bilayers agree perfectly with experiments, validating the simulation model and methods. For the comparison with theory, it is important to split the simulated total surface interaction force into a direct contribution from surface−surface molecular interactions and an indirect water-mediated contribution. We find the indirect hydration force and the structural water-ordering profiles from the simulations to be in perfect agreement with the predictions from theoretical models that account for the surface-induced water ordering, which strongly supports the water-structuring hypothesis for the hydration force. However, the comparison between the simulations for polar surfaces with different headgroup architectures reveals significantly different decay lengths of the indirect water-mediated hydration-force, which for laterally homogeneous water structuring would imply different bulk-water properties. We conclude that laterally inhomogeneous water ordering, induced by laterally inhomogeneous surface structures, shapes the hydration repulsion between polar surfaces in a decisive manner. Thus, the indirect water-mediated part of the hydration repulsion is caused by surface-induced water structuring but is surface-specific and thus nonuniversal.

show abstract

Continuum theories of structured dielectrics

Cited by 4 publications

References 53 publications

A comprehensive continuum theory of structured liquids

A comprehensive continuum theory of structured liquids

Deconstructing Electrostatics of Functionalized Metal Nanoparticles from Molecular Dynamics Simulations

Water Structuring Induces Nonuniversal Hydration Repulsion between Polar Surfaces: Quantitative Comparison between Molecular Simulations, Theory, and Experiments

Contact Info

Product

Resources

About