Structures and properties of induced lyotropic cholesteric phases

Phase chirality in disk-like lyotropic cholesteric phases (Chp) was investi gated, which were induced by center and axial chiral dopants to achiral lyo tropic nematic host phases (N-D). In a lyotropic nematic matrix of the ND p hase in the ternary system hexadecyldimethylethylammoniumbromid (C(16)Me(2) EABr)/water/n-decanol, a disk-like lyotropic cholesteric phase Chp was indu ced by addition of the axial optically active compound R(-)-1,1 ' -binaphth alene-2,2 ' -diyl-hydrogenphosphate (BDP). The HTP value of the BDP is gene rally lower than the HTP value of inducing substances with center chirality as cholesterol, prednisolon etc. At constant composition of the ND phase, the helix lengths were determined in dependence on the BDP concentration by means of evaluation of the "spaghetti-like texture" using polarizing micro scopy. The reciprocal helix-lengths are changing linearly with rising BDP c oncentration. Furthermore selected results of X-ray scattering and diffract ion on the structure formation in the Ch(D) phase were discussed.