1,415 research outputs found
Electrostatic image effects for counter-ions between charged planar walls
We study the effect of dielectric inhomogeneities on the interaction between
two planparallel charged surfaces with oppositely charged mobile charges in
between. The dielectric constant between the surfaces is assumed to be
different from the dielectric constant of the two semiinfinite regions bounded
by the surfaces, giving rise to electrostatic image interactions. We show that
on the weak coupling level the image charge effects are generally small, making
their mark only in the second order fluctuation term. However, in the strong
coupling limit, the image effects are large and fundamental. They modify the
interactions between the two surfaces in an essential way. Our calculations are
particularly useful in the regime of parameters where computer simulations
would be difficult and extremely time consuming due to the complicated nature
of the long range image potentials.Comment: 21 pages, 8 figure
Counterion-mediated Electrostatic Interactions between Helical Molecules
We study the interaction of two cylinders with helical charge distribution
mediated by neutralizing counterions, by analyzing the separation as well as
the azimuthal angle dependence of the interaction force in the weak and strong
coupling limit. While the azimuthal dependence of the interaction in the weak
coupling limit is overall small and mostly negligible, the strong coupling
limit leads to qualitatively new features of the interaction, among others also
to an orientationally dependent optimal configuration that is driven by angular
dependence of the correlation attraction. We investigate the properties of this
azimuthal ordering in detail and compare it to existing results.Comment: 11 pages, 12 figure
Confined chiral polymer nematics: ordering and spontaneous condensation
We investigate condensation of a long confined chiral nematic polymer inside
a spherical enclosure, mimicking condensation of DNA inside a viral capsid. The
Landau-de Gennes nematic free energy {\sl Ansatz} appropriate for nematic
polymers allows us to study the condensation process in detail with different
boundary conditions at the enclosing wall that simulate repulsive and
attractive polymer-surface interactions. Increasing the chirality, we observe a
transformation of the toroidal condensate into a closed surface with an
increasing genus, akin to the ordered domain formation observed in
cryo-microscopy of bacteriophages
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