Freeze-Fracture Electron Microscopy Study of Lamellate Phase in a Sodium Dodecylsulfate-Formamide (SDS-Formamide) System

Abstract

We highlighted by freeze-fracture the lamellate phase Lα (ID) in SDS-formamide system. This phase succeeds in increasing concentration into surfactant with the cubic phase Qα (Ia3d). The lamellate phase is observed in electron microscopy and corresponds to high values of the concentrations into amphiphilic going up to 100%. Of this fact it is easily vitrified by hardening. Our work enabled us to observe in the system SDS-formamide two possible morphologies of the phase Lα: smooth fractures presenting the setbacks in which appears a periodicity, and fractures revealing stacking of plates of decreasing diameter, forming kinds of turrets. In this second case, we give an explanation of the formation of the towers based on germination and growth theory.