Micellar shape anisotropy and elastic constants in discotic lyotropic liquid crystals

The elastic constants of a discotic lyotropic nematic liquid crystal are ca lculated by means of a pseudomolecular approach as functions of the micella r shape anisotropy. By assuming that the temperature dependence of the rati o of the elastic constants comes from the temperature dependence of the mic ellar shape anisotropy, the theoretical predictions are connected with expe rimental measurements for the ratio K-33/K-11. This procedure permits one t o determine, in a phenomenological way, the temperature dependence for the ratio of elastic constants and for the micellar shape anisotropy near the n ematic-isotropic transition in agreement with the experimental data. [S1063 -651X(99)15410-2].