Late-time coarsening dynamics in a nematic liquid crystal

Abstract

We have studied the coarsening dynamics of line defects in the uniaxial nematic liquid crystal 4-cyano-4’-n-pentylbiphenyl, subjected to a rapid pressure jump from the isotropic to the nematic phase. At late times, the density of disclination lines ρ is expected to scale with time as ρ∝${\mathit{t}}^{\mathrm{-}\nu }$ with ν=1. We have measured the scaling exponent to be ν=1.02±0.09 over the region 16<ρ<160 ${\mathrm{mm}}^{\mathrm{-}2}$. In addition, we have measured the collapse of loops consisting of type-1/2 disclination lines. The loop radius r is expected to scale with time as r∝(${\mathit{t}}_0$-t${)}^{\mathrm{\alpha }}$, where α=1/2 and ${\mathit{t}}_0$ is the time at which the loop vanishes. We found α to be 0.50±0.03.