Ion Distribution in an Isolated Charged NanoSpherical Cavity: A DFT Study

In this paper, we present a perturbative density functional theory (DFT) in cooperate byperturbation theory for describing the density profiles of negative and positive ions in an isolatedspherical cavity that there is a steady charge on it. A density-functional theory is used on theframework of the restricted primitive model that the ions have same size and the solvent isrepresented by a dielectric continuum [1].According to the results the density of ion and also the mean electrostatic potentialincrease, with increasing surface charge Q. Also, the difference between the positive andnegative ions increases with Q, for example, at a concentration of 1 M, monovalent ions in thecavity whit radius of R/σ =1.5, coions is not seen against counterions, but mean electrostaticpotential is still positive. Moreover by increasing the surface charge on the surface of sphericalpore, the two species are separated from each other. Obviously, as the surface charge is higher,the counterions are more entrained until the distribution of the ions is restricted to thecounterions.

کلیدواژه ها:

DFT ، Isolated Charged Spherical Cavity ، Ion Distribution