Electroconvection of a nematic liquid crystal in polymer networks as porous media

The polymer network liquid crystal (PNLC), in which a polymer network is formed within a nematic liquid crystal, can be regarded as a porous medium. In this study, we discover electroconvection in the PNLC and examine its nonlinear, nonequilibrium physical properties. As the monomer weight fraction increases, distortions in the convective pattern emerge and the temporal fluctuations slow. The polymer network hinders the reorientation of the liquid crystal molecules, thereby suppressing the motion of the convection pattern. Furthermore, measurements of the electric Nusselt number, which characterizes the electrical transport phenomena, reveal that, as the monomer weight fraction increased, the threshold voltage for the onset of convection increased and the efficiency of charge transport decreased. This study quantitatively evaluated the nonlinear, nonequilibrium phenomena of the PNLC as flow phenomena in porous media.