  The competition of depletion attractions and longer-ranged repulsions between
colloidal particles in colloid-polymer mixtures leads to the formation of
heterogeneous gel-like structures. For instance, gel networks, i.e., states
where the colloids arrange in thin strands that span the whole system occur at
low packing fractions for attractions that are stronger than those at the
binodal line of equilibrium liquid-fluid phase separation. By using Brownian
dynamics simulations we explore the formation, structure, and ageing dynamics
of gel networks. We determine reduced network that focus on the essential
connections in a gel network. We compare the observed properties to those of
bulky gels or cluster fluids. Our results demonstrate that both the structure
as well as the (often slow) dynamics of the stable or meta-stable heterogenous
states in colloid-polymer mixtures possess distinct features on various length
and time scales and thus are richly divers.
