6,290 research outputs found
Letter from Sidney Frigand, Director of Public Affairs for the Port Authority of New York, to Geraldine Ferraro
Congratulatory letter from Sidney J. Frigand, Director of Public Affairs for the Port Authority of New York, to Geraldine Ferraro. Includes standard response letter from Ferraro, and a data entry sheet.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_new_york/1234/thumbnail.jp
Inverted critical adsorption of polyelectrolytes in confinement
What are the fundamental laws for the adsorption of charged polymers onto
oppositely charged surfaces, for convex, planar, and concave geometries? This
question is at the heart of surface coating applications, various complex
formation phenomena, as well as in the context of cellular and viral
biophysics. It has been a long-standing challenge in theoretical polymer
physics; for realistic systems the quantitative understanding is however often
achievable only by computer simulations. In this study, we present the findings
of such extensive Monte-Carlo in silico experiments for polymer-surface
adsorption in confined domains. We study the inverted critical adsorption of
finite-length polyelectrolytes in three fundamental geometries: planar slit,
cylindrical pore, and spherical cavity. The scaling relations extracted from
simulations for the critical surface charge density -defining the
adsorption-desorption transition-are in excellent agreement with our analytical
calculations based on the ground-state analysis of the Edwards equation. In
particular, we confirm the magnitude and scaling of for the concave
interfaces versus the Debye screening length and the extent of
confinement for these three interfaces for small values. For
large the critical adsorption condition approaches the planar limit.
The transition between the two regimes takes place when the radius of surface
curvature or half of the slit thickness is of the order of . We
also rationalize how gets modified for semi-flexible versus
flexible chains under external confinement. We examine the implications of the
chain length onto critical adsorption-the effect often hard to tackle
theoretically-putting an emphasis on polymers inside attractive spherical
cavities.Comment: 12 pages, 10 figures, RevTe
The neutron star inner crust and symmetry energy
The cell structure of clusters in the inner crust of a cold \beta-equilibrium
neutron star is studied within a Thomas Fermi approach and compared with other
approaches which include shell effects. Relativistic nuclear models are
considered. We conclude that the symmetry energy slope L may have quite
dramatic effects on the cell structure if it is very large or small. Rod-like
and slab-like pasta clusters have been obtained in all models except one with a
large slope L.Comment: 16 pages, 5 figure
Critical adsorption of polyelectrolytes onto charged Janus nanospheres
Based on extensive Monte Carlo simulations and analytical considerations we
study the electrostatically driven adsorption of flexible polyelectrolyte
chains onto charged Janus nanospheres. These net-neutral colloids are composed
of two equally but oppositely charged hemispheres. The critical binding
conditions for polyelectrolyte chains are analysed as function of the radius of
the Janus particle and its surface charge density, as well as the salt
concentration in the ambient solution. Specifically for the adsorption of
finite-length polyelectrolyte chains onto Janus nanoparticles, we demonstrate
that the critical adsorption conditions drastically differ when the size of the
Janus particle or the screening length of the electrolyte are varied. We
compare the scaling laws obtained for the adsorption-desorption threshold to
the known results for uniformly charged spherical particles, observing
significant disparities. We also contrast the changes to the polyelectrolyte
chain conformations and the binding energy distributions close to the
adsorption-desorption transition for Janus nanoparticles to those for simple
spherical particles. Finally, we discuss experimentally relevant
physico-chemical systems for which our simulations results may become
important. In particular, we observe similar trends with polyelectrolyte
complexation with oppositely but heterogeneously charged proteins.Comment: 13 pages, 11 figures, RevTeX
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