Elasticities and viscosities of a lyotropic chromonic nematic liquid crystal

We have performed dynamic light scattering studies of the elastic moduli and viscosity coefficients in a uniformly aligned sample of a lyotropic chromonic nematic formed by 14 wt. {\%} water solution of Disodium Cromoglycate [1]. These parameters show a significant anisotropy. In particular, the bend and splay moduli $K_{33}$ and $K_{11}$ are an order of magnitude higher than the twist modulus $K_{22}$, and the ratio $K_{33}/K_{11}$ shows an anomalous increase in temperature, which we attribute to the shortening of the aggregates. The bend viscosity is three orders of magnitude smaller than the splay and twist viscosities; all viscosity coefficients exhibit a strong temperature dependence. \\[4pt] [1] Nastishin \textit{et al.}, \textit{Phys. Rev. E.} \textbf{70}, 051706 (2004).