scholarly journals On the Role of Electrostatic Repulsion in Topological Defect-Driven Membrane Fission

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 812
Author(s):  
Ekaterina Gongadze ◽  
Luka Mesarec ◽  
Samo Kralj ◽  
Veronika Kralj-Iglič ◽  
Aleš Iglič
Keyword(s):  
Osmotic Pressure ◽  
Electric Fields ◽  
Double Layers ◽  
Parent Cell ◽  
Charged Surfaces ◽  
Membrane Fission ◽  
Membrane Protrusions ◽  
Electric Potentials ◽  
Poisson Boltzmann ◽  
Boltzmann Model

Within a modified Langevin Poisson–Boltzmann model of electric double layers, we derived an analytical expression for osmotic pressure between two charged surfaces. The orientational ordering of the water dipoles as well as the space dependencies of electric potentials, electric fields, and osmotic pressure between two charged spheres were taken into account in the model. Thus, we were able to capture the interaction between the parent cell and connected daughter vesicle or the interactions between neighbouring beads in necklace-like membrane protrusions. The predicted repulsion between them can facilitate the topological antidefect-driven fission of membrane daughter vesicles and the fission of beads of undulated membrane protrusions.

Ionic Layering and Overcharging in Electrical Double Layers in a Poisson-Boltzmann Model

2020 ◽  
Vol 125 (18) ◽  
Author(s):  
Ankur Gupta ◽  
Ananth Govind Rajan ◽  
Emily A. Carter ◽  
Howard A. Stone
Keyword(s):  
Double Layers ◽  
Electrical Double Layers ◽  
Poisson Boltzmann ◽  
Boltzmann Model ◽  
Ionic Layering

scholarly journals Attraction between two similar particles in an electrolyte: effects of Stern layer absorption

2010 ◽  
Vol 82 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Franck Plouraboué ◽  
Hua-Chia Chang
Keyword(s):  
Potential Problem ◽  
Debye Length ◽  
Mean Field ◽  
Static Condition ◽  
Double Layers ◽  
Stationary Potential ◽  
Identical Particles ◽  
Poisson Boltzmann ◽  
Boltzmann Model ◽  
Cylindrical Particles

When Debye length is comparable or larger than the distance between two identical particles, the overlapping among the particles double-layers can play an important role in their interactions. This paper presents a theoretical analysis of the interaction among two identical particles with overlapped double-layers. We particularly focus on the effect of a Stern electro static condition from linearization of the adsorption isotherm near the isoelectric (neutrality) point in order to capture how polyvalent ion condensation affect sand reverses the surface charge. The stationary potential problem is solved within the framework of an asymptotic lubrication approach for a mean-field Poisson-Boltzmann model. Both spherical and cylindrical particles are analyzed. The results are finally discussed in the context of Debye-Hückel (D-H) limit and beyond it.

scholarly journals A gateway for ion transport on gas bubbles pinned onto solids

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Veton Haziri ◽  
Tu Pham Tran Nha ◽  
Avni Berisha ◽  
Jean-François Boily
Keyword(s):  
Ion Transport ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
Gas Bubbles ◽  
Open Circuit ◽  
Double Layers ◽  
Water Geochemistry ◽  
Chemical Potentials ◽  
Pore Water Geochemistry ◽  
Electric Potentials

AbstractGas bubbles grown on solids are more than simple vehicles for gas transport. They are charged particles with surfaces populated with exchangeable ions. We here unveil a gateway for alkali metal ion transport between oxygen bubbles and semi-conducting (iron oxide) and conducting (gold) surfaces. This gateway was identified by electrochemical impedance spectroscopy using an ultramicroelectrode in direct contact with bubbles pinned onto these solid surfaces. We show that this gateway is naturally present at open circuit potentials, and that negative electric potentials applied through the solid enhance ion transport. In contrast, positive potentials or contact with an insulator (polytetrafluoroethylene) attenuates transport. We propose that this gateway is generated by overlapping electric double layers of bubbles and surfaces of contrasting (electro)chemical potentials. Knowledge of this ion transfer phenomenon is essential for understanding electric shielding and reaction overpotential caused by bubbles on catalysts. This has especially important ramifications for predicting processes including mineral flotation, microfluidics, pore water geochemistry, and fuel cell technology.

scholarly journals The crystallization enthalpy and entropy of protein solutions: microcalorimetry, van't Hoff determination and linearized Poisson–Boltzmann model of tetragonal lysozyme crystals

2021 ◽  
Vol 23 (4) ◽  
pp. 2686-2696
Author(s):  
Lorena Hentschel ◽  
Jan Hansen ◽  
Stefan U. Egelhaaf ◽  
Florian Platten
Keyword(s):  
Theoretical Description ◽  
Protein Solutions ◽  
Consistent Picture ◽  
Poisson Boltzmann ◽  
Enthalpy And Entropy ◽  
Boltzmann Model ◽  
Lysozyme Crystals ◽  
Solution Parameters

Microcalorimetric and van't Hoff determinations as well as a theoretical description provide a consistent picture of the crystallization enthalpy and entropy of protein solutions and their dependence on physicochemical solution parameters.

scholarly journals Double layers in the downward current region of the aurora

2003 ◽  
Vol 10 (1/2) ◽  
pp. 45-52 ◽  
Author(s):  
R. E. Ergun ◽  
L. Andersson ◽  
C. W. Carlson ◽  
D. L. Newman ◽  
M. V. Goldman
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Phase Space ◽  
Electric Field ◽  
Electric Fields ◽  
Double Layers ◽  
Parallel Electric Field ◽  
Electrostatic Waves ◽  
Current Region ◽  
Decisive Evidence

Abstract. Direct observations of magnetic-field-aligned (parallel) electric fields in the downward current region of the aurora provide decisive evidence of naturally occurring double layers. We report measurements of parallel electric fields, electron fluxes and ion fluxes related to double layers that are responsible for particle acceleration. The observations suggest that parallel electric fields organize into a structure of three distinct, narrowly-confined regions along the magnetic field (B). In the "ramp" region, the measured parallel electric field forms a nearly-monotonic potential ramp that is localized to ~ 10 Debye lengths along B. The ramp is moving parallel to B at the ion acoustic speed (vs) and in the same direction as the accelerated electrons. On the high-potential side of the ramp, in the "beam" region, an unstable electron beam is seen for roughly another 10 Debye lengths along B. The electron beam is rapidly stabilized by intense electrostatic waves and nonlinear structures interpreted as electron phase-space holes. The "wave" region is physically separated from the ramp by the beam region. Numerical simulations reproduce a similar ramp structure, beam region, electrostatic turbulence region and plasma characteristics as seen in the observations. These results suggest that large double layers can account for the parallel electric field in the downward current region and that intense electrostatic turbulence rapidly stabilizes the accelerated electron distributions. These results also demonstrate that parallel electric fields are directly associated with the generation of large-amplitude electron phase-space holes and plasma waves.

Poisson-Boltzmann model in a solvent of interacting Langevin dipoles

2009 ◽  
Vol 88 (1) ◽  
pp. 14003 ◽  
Author(s):  
D. H. Mengistu ◽  
K. Bohinc ◽  
S. May
Keyword(s):  
Poisson Boltzmann ◽  
Langevin Dipoles ◽  
Boltzmann Model

scholarly journals Electric fields and double layers in plasmas

1987 ◽  
Vol 5 (2) ◽  
pp. 233-255 ◽  
Author(s):  
Nagendra Singh ◽  
H. Thiemann ◽  
R. W. Schunk
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Electric Fields ◽  
Sheet Thickness ◽  
High Density ◽  
Effective Length ◽  
Double Layers ◽  
Low Density ◽  
Ambient Magnetic Field ◽  
Cold Plasmas

Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamic features of the double layers are discussed. These features, as seen in simulations, laboratory experiments and theory, indicate that double layers and the currents through them undergo slow oscillations, which are determined by the ion transit time across an effective length of the system in which the double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations have been considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields (parallel to an ambient magnetic field) and double layers in an expanding plasma are discussed.

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