Effect of Protic Solvents on the Formation of Lyotropic K-Myristinate Mesophases: Texture Observations and Binary Phase Diagrams

Abstract

The phase diagrams of following binary soap systems (soap = K-myristinate = KC₁₄) were examined by polarization microscopy: system KC₁₄/glycerol (G), KC₁₄/ethylene glycol (E) and KC₁₄/butylene glycol (E). Comparing these three phase diagrams, we found alterations in types of phase diagrams that depends on the chemical structure of the solvent. The following polymorphism were observed: In the system KC₁₄/G: C↭G↭H↭I↭L↭S (C = crystalline phase, G = gel phase, H = hexagonal phase, I = isotropic phase, L = lamellar phase, S = isotropic solution). In the system KC₁₄/E: C↭G↭L↭S and in the system KC₁₄/B the same phase sequence: C↭G↭L↭S.

The differences in number, position, extension and sequence of occurring lyotropic mesophases are a function of the composition in the binary system and temperatures. The influence, which the solution medium exerts on the formation of structures in the binary systems, is distinct and pronounced.

Key Words:

• Lyotropic mesophases
• phase diagrams
• polymorphism
• protic solvents
• K-myristinate