arXiv subjects

István P. Sugár

Publications and source records attributed to István P. Sugár.

4 recordsLinked to original sources

arXiv2021

Interaction energy between two charged spheres surrounded by electrolyte. The smaller sphere located inside the larger sphere

By using the recently generalized version of Newton Shell Theorem [3] analytical equations are derived to calculate the electric interaction energy between two charged spheres, a small one is located within a larger one, and each sphere is surrounded outside and inside by electrolyte. This electric interaction energy is calculated as a function of the electrolyte ion concentration, temperature, distance between the centers and size of the spheres. At the same distance between the centers of the spheres the absolute value of the interaction energy decreases with increasing electrolyte ion concentration and increases with increasing temperature. At zero electrolyte ion concentration the derived analytical equation transforms into the result of the Shell Theorem. Finally, the analytical equation is generalized to calculate the total electric interaction energy between a large charged sphere and N small charged spheres (located within the large sphere) where the spheres are surrounded by electrolyte.

cond-mat.soft↗

arXiv2021

Interaction energy between two separated charged spheres surrounded inside and outside by electrolyte

By using the recently generalized version of Newton Shell Theorem analytical equations are derived to calculate the electric interaction energy between two separated charged spheres surrounded outside and inside by electrolyte. This electric interaction energy is calculated as a function of the electrolyte ion concentration, temperature, distance between the spheres and size of the spheres. At the same distance between the spheres the absolute value of the interaction energy decreases with increasing electrolyte ion concentration and increases with increasing temperature. At zero electrolyte ion concentration the derived analytical equation transforms into the Coulomb equation. Finally, the analytical equation is generalized to calculate the electric interaction energy of N separated charged spheres surrounded by electrolyte.

cond-mat.soft↗

arXiv2021

On the cause of Zeta potential of a charged vesicle. The extra- and intravesicular membrane charges contribute differently to the extra- and intravesicular potential

When the charge densities on the inner and outer surface of the vesicle membrane are similar one may assume that the potential at a point closer to the outer/inner surface is more affected by the charges located at the outer/inner surface of the vesicle membrane. However, because of the curvature of the vesicle and the screening effect of the electrolyte ions the situation is more complicated. When the charge densities at the inner and outer surface of the vesicle membrane are the same then at any finite distance Z from the center of the vesicle the contribution of the charges, located at the outer membrane surface, to the vesicle potential Vex is different from the contribution of the charges, located at the inner membrane surface, to the vesicle potential Vin. At low electrolyte ion concentrations (from C=0 to 0.00001 [Mol]) Vex/Vin>1 and increases with increasing distance from the center of the vesicle until the external surface of the vesicle membrane. With further increasing distance Vex/Vin remains constant at C=0 [Mol], while at C>0 [Mol] it starts decreasing. However, at high electrolyte ion concentrations (C>0.01 [Mol]) with increasing distance from the center of the vesicle Vex/Vin reaches its maximum at the internal surface of the vesicle membrane. With further increasing distance, close to the outer surface of the vesicle Vex/Vin becomes less than 1 (i.e. the charges at the inner surface of the membrane contribute to the potential more than the charges at the outer surface). Further increasing the distance Vex/Vin reaches its minimum and then increases to 1 (i.e. the charges at the inner surface of the membrane contribute to the potential like the charges at the outer surface of the membrane). With increasing electrolyte ion concentration the minimum of Vex/Vin is getting deeper (approaching zero) and its location is getting closer to the outer surface of the vesicle.

cond-mat.soft↗

arXiv2020

A Generalization of Shell Theorem. Electric Potential of Charged Spheres and Charged Vesicles Surrounded by Electrolyte

By using the Debye screened potential a generalized version of Newton's Shell Theorem is developed and analytical equations are derived to calculate i) the potential of a charged sphere surrounded by electrolyte, ii) the potential of two concentric charged spheres surrounded by electrolyte, and iii) the membrane potential of a charged lipid vesicle surrounded by electrolyte with high ion concentration. By numerical integration the potential of a lipid vesicle is calculated at any electrolyte concentration.

cond-mat.soft↗