Pair interaction of charged colloidal spheres near a charged wall.
Although equally charged colloidal particles dispersed in clean water are expected to repel each other, an unexplained long-range attraction has consistently been reported for charged colloidal spheres confined by charged macroscopic surfaces. We present an alternative equilibrium measurement of the pair interaction energy for charged spheres near a single charged wall. Analyzing their radial distribution functions for different concentrations reveals a purely repulsive sphere-sphere interaction that is well described by a screened Coulomb potential.
Behrens
S H
SH
Department of Physics, James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
Grier
D G
DG