Smectic Capillary Condensation

The pre-smectic interaction is therefore observable already in the isotropic phase, although there is no direct phase transition from the isotropic to the smectic-A phase in 8CB. This makes the capillary condensation of the smectic-A phai in the gap between the surfaces impossible and consequently enables more detailed observation of the presmectic interaction. In the case when there is a direct isotropic-smectic-A phase transition, like for example in 12CB, a condensation phenomenon similar to nematic capillary condensation is observable. 

When the liquid crystal exhibits a direct isotropic to smectic-A phase transition, the capillary condensation of the smectic phase in a gap between the surfaces is possible, since the isotropic to smectic-A phase transition is a first order phase transition due to the coupling between the nematic and smectic order parameters [26]. 

Fig. 3.9. Capillary condensation of the smectic phase in 12CB. The temperature...

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