ao8b01393_si_001.pdf (1.16 MB)
Electrostatics of Nanoparticle–Wall Interactions within Nanochannels: Role of Double-Layer Structure and Ion–Ion Correlations
journal contribution
posted on 2018-09-18, 18:33 authored by Inderbir
S. Sidhu, Amalie L. Frischknecht, Paul J. AtzbergerWe
perform computational investigations of the electrolyte-mediated interactions of charged
nanoparticles with the walls of nanochannels. We investigate the role
of discrete ion effects, valence, and electrolyte strength on nanoparticle–wall
interactions. We find for some of the multivalent charge regimes that
the like-charged nanoparticles and walls can have attractive interactions.
We study in detail these interactions and the free-energy profile
for the nanoparticle–wall separation. We find there are energy
barriers and energy minima giving preferred nanoparticle locations
in the channel near the center and at a distance near to but separated
from the channel walls. We characterize contributions from surface
overcharging, condensed layers, and overlap of ion double layers.
We perform our investigations using coarse-grained particle-level
simulations with Brownian dynamics, classical density functional theory,
and the mean-field Poisson–Boltzmann theory. We discuss the
implications of our results for phenomena in nanoscale devices.