Critical adsorption of polyelectrolytes onto charged Janus nanospheres

• Main Authors: de Carvalho, Sidney J, Metzler, Ralf, Cherstvy, Andrey G
• Format: Journal Article
• Language: English
• Published: 23-12-2014
• Subjects: Physics - Biological Physics; Physics - Soft Condensed Matter
• DOI: 10.48550/arxiv.1412.7474

Phys. Chem. Chem. Phys. 16, 15539 (2014) 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.