Gel and Glass Transitions in Short-Range Attractive Colloidal Systems - Food Colloids: Self-Assembly and Material Science - page 338

Figure 7 Upper plot shows pore distribution function P(x) at the initial and final
configurations for three representative densities. Lower plot shows evolution
in time of pore distribution function for the case f ¼ 0.25; the energy is plotted
versus time in the inset. The arrows indicate the time at which the pore
distribution function is evaluated
function to other observables, we also show in the inset the evolution of the
energy. During the first stage, the peak of P(r) does not move. The only change
is in the height of the peak, which displays a limited growth, indicating an initial
local rearrangement of the particles. In a second stage the peak disappears,
following the decrease of the energy, and at same time the pore distribution gets
wider, i.e., the pores are growing in size. This confirms that the fast drop in
energy and the formation of the open structure proceed simultaneously.
22.3 Dependence on Range of Attraction: Can an
Arrested State Emerge from Equilibrium?
In the previous section we discussed how a gel can be obtained by quenching
the system into the phase separation region. A question remains open: is it
possible to arrest the system without the strong density fluctuations that
enhance the formation of open structures?
One of the possibilities that have been explored in the past is the control of
the dynamics by varying the range of attraction. Indeed, within MCT there is a
critical interaction range below which the attractive glass line takes over the
phase separation, 20 and this feature has been used to interpret experimental