M. Lemercier et al., LIQUID-SOLID PHASE-TRANSFORMATION OF A 2-COMPONENT SYSTEM (1,2-1,4 CHLORONITROBENZENES) HELD INSIDE POROUS MATERIALS, Revue générale de thermique, 35(412), 1996, pp. 219-231
The liquid-solid phase changes of a perfect solution (1,2-1,4 chloroni
trobenzenes) held inside porous materials of known textural characteri
stics have been studied by using a DSC technique. When the pores are s
aturated with the condensate, the successive steps of equilibrium crys
tallization depend on whether the porous volume can be filled or not w
ith the eutectic liquid. By varying the amount and initial composition
of the solution used, the composition of the condensate which crystal
lizes inside the biggest pores of a given porous material, can be adju
sted. By measuring the corresponding temperature, it is then possible
to determine the phase diagram of the binary system in a given state o
f division. The equilibrium curves are similar to those of bulk binary
systems for the two considered states of division. They are all the m
ore shifted towards lower temperatures as the capillary condensate is
more finely divided. The temperature shift depends on the composition,
like the ratio of the solution-crystal 1,2 (or 1,4) interfacial tensi
on to the partial volumic entropy of transition of the 1,2 (respective
ly 1,4) component.