ABSTRACT
I. INTRODUCTION Surfactants are amphipathic molecules, generally characterized by the pres ence of two distinctly different regions in the same molecule: a lipophilic part (restrictively called hydrophobic) and a lipophobic or hydrophilic portion. The existence in the same molecule of two moieties, one with an affinity for the solvent and the other antipathetic to it, is termed amphiphily or amphipathy. Surface-active agents constitute a versatile class of natural or synthetic com pounds. They may contain a large variety of polar ionic or nonionic parts (called head) and apolar moieties (named tail), generally consisting of long hydrocarbon chains [1-5]. This dual nature is responsible for the phenomena of surface activity and of micellization, the formation of molecular organized systems [6] (lamellar phases, liquid crystals, vesicles, etc.), and their capacity of solubilization by forming emulsions and microemulsions [1-6].
