2,529 research outputs found
A modified Poisson-Boltzmann theory: Effects of co-solvent polarizability
In this paper within a field-theoretical approach taking into account
explicitly a co-solvent with a nonzero dipole and a polarizability tensor, we
derive a modified Poisson-Boltzmann equation. Applying the modified
Poisson-Boltzmann equation, we formulate a generalized Gouy-Chapman theory for
the case when an electrolyte solution is mixed with a polar co-solvent having a
large polarizability. We show that an increase of the co-solvent concentration
as well as the co-solvent polarizability lead to a significant increase of
differential capacitance at sufficiently high surface potentials of the
electrode, whereas the profile of the electrostatic potential becomes
considerably more long-ranged. On the contrary, an increase in the permanent
dipole of the co-solvent only weakly affects the differential capacitance
A flexible polymer chain in a critical solvent: Coil or globule?
We study the behavior of a flexible polymer chain in the presence of a
low-molecular weight solvent in the vicinity of a liquid-gas critical point
within the framework of a self-consistent field theory. The total free energy
of the dilute polymer solution is expressed as a function of the radius of
gyration of the polymer and the average solvent number density within the
gyration volume at the level of the mean-field approximation. Varying the
strength of attraction between polymer and solvent we show that two
qualitatively different regimes occur at the liquid-gas critical point. In case
of weak polymer-solvent interactions the polymer chain is in a globular state.
On the contrary, in case of strong polymer-solvent interactions the polymer
chain attains an expanded conformation. We discuss the influence of the
critical solvent density fluctuations on the polymer conformation. The reported
effect could be used to excert control on the polymer conformation by changing
the thermodynamic state of the solvent. It could also be helpful to estimate
the solvent density within the gyration volume of the polymer for drug delivery
and molecular imprinting applications
Interface states in junctions of two semiconductors with intersecting dispersion curves
A novel type of shallow interface state in junctions of two semiconductors
without band inversion is identified within the envelope function
approximation, using the two-band model. It occurs in abrupt junctions when the
interband velocity matrix elements of the two semiconductors differ and the
bulk dispersion curves intersect. The in-plane dispersion of the interface
state is found to be confined to a finite range of momenta centered around the
point of intersection. These states turn out to exist also in graded junctions,
with essentially the same properties as in the abrupt case.Comment: 1 figur
On the Ado Theorem for finite Lie conformal algebras with Levi decomposition
We prove that a finite torsion-free conformal Lie algebra with a splitting
solvable radical has a finite faithful conformal representation.Comment: 11 page
Conductance through the disclination dipole defect in metallic carbon nanotubes
The electronic transport properties of a metallic carbon nanotube with the
five-seven disclination pair characterized by a lattice distortion vector are
investigated. The influence of the disclination dipole includes induced
curvature and mixing of two sublattices. Both these factors are taken into
account via a self-consistent perturbation approach. The conductance and the
Fano factor are calculated within the transfer-matrix technique. PACS:
73.63.Fg, 72.80.Rj, 72.10.F
Stability and hyperfine structure of the four- and five-body muon-atomic clusters and
Based on the results of accurate variational calculations we demonstrate
stability of the five-body negatively charged ions . Each of these five-body ions contains two electrons , one
negatively charged muon and two nuclei of the hydrogen isotopes . The bound state properties of these five-body ions, including
their hyperfine structure, are briefly discussed. We also investigate the
hyperfine structure of the ground states of the four-body muonic quasi-atoms
. In particular, we determine the hyperfine
structure splittings for the ground state of the four-body muonic quasi-atoms:
and
- …