LYOTROPIC NEMATICS - MOLECULAR AGGREGATION AND SUSCEPTIBILITIES

Alterations of the concentrations of certain components in a lyotropic nematic mesophase may change the sign of the anisotropy of its magnetic susceptibility, DELTA // chi . The determination of the sign of DELTA // chi by optical observation of the textures in the presence of a magnetic field, the results of an X-ray diffraction study of the aggregation of the amphiphilic molecules are reported concluding that the inversion of DELTA // chi results from the different shapes of the aggregates.