Colloidal monolayer trapped near a charged wall: a synchrotron x-ray diffraction study.
Using x-ray diffraction from microfluidic channel arrays, we have determined concentration profiles of charge-stabilized silica colloids (radius 60+/-2 nm) confined between two like-charged dielectric walls at a few hundred nanometer distance. In solutions of very low ionic strength, strongly repulsive Coulomb interactions drive the colloids toward the central region between the walls. The addition of a small quantity of salt ions (0.2 mM) causes a dense colloidal monolayer to be trapped near the walls.
Satapathy
D K
DK
Research Department of Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. dillip.satapathy@psi.ch
Bunk
O
O
Jefimovs
K
K
Nygård
K
K
Guo
H
H
Diaz
A
A
Perret
E
E
Pfeiffer
F
F
David
C
C
Wegdam
G H
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van der Veen
J F
JF