Ions confined in spherical dielectric cavities modeled by a splitting fieldtheory.
(2015) In Journal of Chemical Physics 142(14). Abstract
 The properties of ions confined within spherical dielectric cavities are examined by a splitting fieldtheory and Monte Carlo simulations. Three types of cavities are considered: one possessing a uniform surface charge density, one with a uniform volume charge density, and one containing mobile ions. In all cases, mobile counterions are present within the dielectric sphere. The splitting theory is based on dividing the electrostatic interaction into long and shortwavelength contributions and applying different approximations on the two contributions. The splitting theory works well for the case where the dielectric constant of the confining sphere is equal to or less than that of the medium external to the sphere. Nevertheless, by... (More)
 The properties of ions confined within spherical dielectric cavities are examined by a splitting fieldtheory and Monte Carlo simulations. Three types of cavities are considered: one possessing a uniform surface charge density, one with a uniform volume charge density, and one containing mobile ions. In all cases, mobile counterions are present within the dielectric sphere. The splitting theory is based on dividing the electrostatic interaction into long and shortwavelength contributions and applying different approximations on the two contributions. The splitting theory works well for the case where the dielectric constant of the confining sphere is equal to or less than that of the medium external to the sphere. Nevertheless, by extending the theory with a virial expansion, the predictions are improved. However, when the dielectric constant of the confining sphere is greater than that of the medium outside the sphere, the splitting theory performs poorly, only qualitatively agreeing with the simulation data. In this case, the strongcoupling expansion does not seem to work well, and a modified meanfield theory where the counterions interact directly with only their own image charge gives improved predictions. The splitting theory works best for the system with a uniform surface charge density and worst for the system with a uniform volume charge density. Increasing the number of ions within the sphere, at a fixed radius, tends to increase the ion density near the surface of the sphere and leads to a depletion region in the sphere interior; however, varying the ion number does not lead to any qualitative changes in the performance of the splitting theory. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/5341770
 author
 Lue, Leo and Linse, Per ^{LU}
 organization
 publishing date
 2015
 type
 Contribution to journal
 publication status
 published
 subject
 in
 Journal of Chemical Physics
 volume
 142
 issue
 14
 publisher
 American Institute of Physics
 external identifiers

 pmid:25877592
 scopus:84928494392
 wos:000352969600039
 ISSN
 00219606
 DOI
 10.1063/1.4917256
 language
 English
 LU publication?
 yes
 id
 de0ec944fd804dcab8de9961cd110f5f (old id 5341770)
 date added to LUP
 20150522 15:18:02
 date last changed
 20180107 03:50:44
@article{de0ec944fd804dcab8de9961cd110f5f, abstract = {The properties of ions confined within spherical dielectric cavities are examined by a splitting fieldtheory and Monte Carlo simulations. Three types of cavities are considered: one possessing a uniform surface charge density, one with a uniform volume charge density, and one containing mobile ions. In all cases, mobile counterions are present within the dielectric sphere. The splitting theory is based on dividing the electrostatic interaction into long and shortwavelength contributions and applying different approximations on the two contributions. The splitting theory works well for the case where the dielectric constant of the confining sphere is equal to or less than that of the medium external to the sphere. Nevertheless, by extending the theory with a virial expansion, the predictions are improved. However, when the dielectric constant of the confining sphere is greater than that of the medium outside the sphere, the splitting theory performs poorly, only qualitatively agreeing with the simulation data. In this case, the strongcoupling expansion does not seem to work well, and a modified meanfield theory where the counterions interact directly with only their own image charge gives improved predictions. The splitting theory works best for the system with a uniform surface charge density and worst for the system with a uniform volume charge density. Increasing the number of ions within the sphere, at a fixed radius, tends to increase the ion density near the surface of the sphere and leads to a depletion region in the sphere interior; however, varying the ion number does not lead to any qualitative changes in the performance of the splitting theory.}, articleno = {144902}, author = {Lue, Leo and Linse, Per}, issn = {00219606}, language = {eng}, number = {14}, publisher = {American Institute of Physics}, series = {Journal of Chemical Physics}, title = {Ions confined in spherical dielectric cavities modeled by a splitting fieldtheory.}, url = {http://dx.doi.org/10.1063/1.4917256}, volume = {142}, year = {2015}, }