  We report the formation of alternating strings and clusters in a binary
suspension of repulsive charged colloids with double layers larger than the
particle size. Within a binary cell model we include many-body and
charge-regulation effects under the assumption of a constant surface potential,
and consider their repercussions on the two-particle interaction potential. We
find that the formation of induced dipoles close to a charge-reversed state may
explain the formation of these structures. Finally, we will touch upon the
formation of dumbbells and small clusters in a one-component system, where the
effective electrostatic interaction is always repulsive.
