Effect of hydrostatic pressure on the Frank splay and bend elastic constants

We report the first systematic work on the effect of hydrostatic pressure on the splay and bend elastic constants of a nematic (N) liquid crystal. At a relative temperature, the magnitudes of both the elastic constants increase significantly with increasing pressure, with the variation for the bend parameter being slightly higher. Pressure also influences the rate at which the elastic constants grow as the smectic A (SmA) phase is approached from the N phase. The studies further show that the temperature range of the N phase may not play an important role in the increase of the splay constant near the transition to the SmA phase.

► First systematic study of the splay and bend elastic constants in the nematic phase at elevated pressures.
► Significant increase of the magnitudes of the elastic constants with pressure at a fixed reduced temperature.
► Enhancement near the transition to the smectic phase increases with pressure.