Colloid and Polymer Science

, Volume 268, Issue 3, pp 264–285

Cubic phases in surfactant and surfactant-like lipid systems

Authors

  • K. Fontell
    • Fysikalisk kemi 1 & 2, KemicentrumLunds Universitet
Colloid Science

DOI: 10.1007/BF01490251

Cite this article as:
Fontell, K. Colloid & Polymer Sci (1990) 268: 264. doi:10.1007/BF01490251

Abstract

Cubic liquid crystalline phases are common in surfactant and surfactant-like lipid systems at temperatures above the Krafft point. They are optically isotropic and very stiff. Therefore, they are often not recognized as independent phases and separated in pure state. The liquid crystalline nature is evidenced by a low-angle diffraction pattern with sharp reflections having Bragg-values above 20 Å coupled with a diffuse wide-angle reflection at 4.5 Å, proving that the hydrocarbon moiety is in a liquid state. The cubic phases occur in a variety of lipid/water systems (also with liquid organic solvents), such as simple soaps, amphiphilic lipids of biological origin, and extracts from membrane lipids. The location of the cubic phases in a phase diagram varies.

The original concept of a cubic structure composed of closed globular aggregates, either of “oil-in-water” or “water-in-oil” type in face-centered array seems to be obsolete. The present structure concepts include closed anisotropic aggregates, short rod-like aggregates forming continuous networks or lamellar aggregates with “zero” curvature forming networks of Infinite Periodic Minimal Surfaces (IPMS). The structure is mostly primitive or body-centered cubic.

Key words

Cubicphasecubicstructuressurfactantsystemssurfactant-likelipidsystems

Copyright information

© Steinkopff 1990