Ternary systems of potassium soap, alcohol, and water: I. Phase equilibria and phase structures

Phase equilibria have been studied at 20°C in the systems potassium caprylate-decanol-water, potassium caprate-octanol-water, and potassium olcate-decanol-water. The boundaries of the regions of the different phases were as a rule determined by centrifuging specimens from the two- and three-phase zones and subsequent analysis of the separated layers. Besides solid crystalline soap, all three systems contain two solution phases and a number of (4–6) mesomorphous phases. X-ray diffraction studies of the structure of the mesophases disclosed two lamellar mesophases and several mesophases with particle structure; of the latter three with Bragg spacing ratios of 1: 1 2 : 1 3 two with a two-dimensional hexagonal structure, and two that are optically isotropic and have a cubic structure. The homogeneous mesophases differ distinctly in appearance under the polarizing microscope.