PHASE-EQUILIBRIA OF TETRAMETHYLDIOCTYLDISILOXANE, WATER AND ORGANIC-SOLVENTS

The phase diagrams for tetramethyldioctyldisiloxane (TDDS), water and several organic components were determined using refractive index, pol arizing microscopy and low angle x-ray diffraction. The solubility lim its of the alcohols were established by quantitative analysis and comp ared to the refractive index of known single phase mixtures. The nonio nic surfactants systems contained isotropic liquids of varying concent rations. Two lyotropic liquid crystal regions were discovered, one of lamellar structure and one consisting of a hexagonal array of closed p acked cylinders. The character of the amphiphiles components to solubi lize the TDDS is reflected in the phase equilibria.