Making the core of a mesogenic particle bulkier could enhance mesophase stability

The liquid crystal phase behaviour of an idealized model, consisting of a linear array of nine soft repulsive spheres, has been studied by Onsager theory with Parsons scaling. Phase transitions have been calculated as a function of the contact distance of the central sphere, σc, with respect to σ, the contact distance of the other beads. For both the isotropic–nematic and nematic–smectic phase transitions, it exists a σ* such that, for σ < σc ⩽ σ*, the phase transition, at a fixed pressure, occurs at a higher temperature than in the case with σc = σ; the opposite happens for σc > σ*. These results could be of interest in the field of fullerene containing liquid crystals.