  Interactions between colloidal particles have hitherto usually been fixed by
the suspension composition. Recent experimental developments now enable the
control of interactions \emph{in-situ}. Here we use Brownian dynamics
simulations to investigate the effect of controlling interactions on gelation,
by "quenching" the system from an equilibrium fluid to a gel. We find that,
contrary to the normal case of an instantaneous quench, where the local
structure of the gel is highly disordered, controlled quenching results in a
gel with a higher degree of local order. Under sufficiently slow quenching,
local crystallisation is found, which is strongly enhanced when a monodisperse
system is used. The higher the degree of local order, the smaller the mean
squared displacement, indicating an enhancement of gel stability.
