DEPLETION EFFECT IN A MODEL LYOTROPIC LIQUID CRYSTAL-THEORY

The effect of added non-adsorbing polymer on the isotropic-nematic pha se transition in a model lyotropic liquid crystal - a suspension of ha rd rods - is studied theoretically. The results indicate that the tran sition is widened and that polymer is partitioned preferentially into the more dilute isotropic phase. The concentration of polymer where a noticeable effect on the transition starts to occur is predicted to be of the order 5 % of the coil overlap threshold c.