Elastic coupling in polymer stabilized ferroelectric liquid crystals

The elastic coupling between a polymer network and liquid crystal has been studied in both the SmA * and SmC * phases of a polymer stabilized ferroelectric liquid crystal polymerized in the SmA * phase. Experimental electric field dependent tilt angle and polarization data are analysed through the SmA * to SmC * transition allowing the full Landau potential to be determined including the polymer network interaction parameter. The elastic coupling between the polymer network and liquid crystal director increases linearly with increasing polymer content. The effect of the network on the system is significant, accounting for approximately 10–15% of the total free energy density. To fully understand the influence of the network further into the SmC * phase, an increasing b -coefficient for increasing polymer concentration needs to be taken into account to describe the change in tilt angle for varying polymer content.