ABSTRACT
I. Introduction 1
II. Reversed Micelles as Nanocontainers: The State of Water and Other Solutes Within Reversed Micelles 8
III. Intermicellar Interactions and Percolation 12
IV. Water-Containing Reversed Micelles as Nanosolvents: The Solubilization of Nonionic Solutes 13
V. Reversed Micelles as Nanoreactors 17
VI. Conclusion 19
References 20
I. INTRODUCTION Apolar molecules interact by means of dispersion forces, which are always attractive independently of their relative orientation, and for this reason they display little tendency to give a long-range ordered molecular arrangement in condensed phases. On the other hand, polar molecules interact also by means of dipoledipole interactions, which are attractive or repulsive depending on the relative orientation of the molecules. It follows that these molecules display a more marked tendency to give a three-dimensionally unlimited ordered molecular arrangement. In the case of amphiphilic molecules, characterized by the coexistence of spatially separated apolar (alkyl chains) and polar moieties, both these parts
concur to drive the intermolecular aggregation giving rise to dimensionally limited supramolecular aggregates. In particular, when dissolved in apolar solvents, as a consequence of both dispersion and dipole-dipole interactions triggered by steric hindrance and thermal agitation, amphiphilic molecules self-assemble, forming a more or less wide spectrum of dynamical structures that differ in aggregation number, shape (linear, cyclic, three-dimensional), and lifetime [1]. Some examples of two-dimensional aggregates of ‘‘amphiphilic molecules’’ (obtained by combining rubber pipette bulbs and magnetic stir bars) oriented according to dipole-dipole interactions are shown in Fig. 1.
