Control of Surfactant Aggregate Structures and Solution Properties through Intermolecular Interactions

Abstract

Amphiphilic substances form various types of aggregate structures depending on their molecular structures and solution conditions. The aggregate structures affect solution properties. For example, the viscosity of aqueous micellar solutions depends on the size and shape of the aggregates. Therefore, the control of aggregate structures corresponds to control of the solution properties. Some intermolecular interactions, such as electrostatic interactions and hydrogen bonding between surfactant molecules, can be used to control aggregate structures. In the present paper, cationic and anionic surfactant mixed systems and amine oxide surfactants systems are described. Cationic and anionic surfactant mixed systems are typical examples of systems that can be used to control electrostatic interactions between molecules. On the other hand, amine oxide surfactant systems have remarkable and different effects on solution properties, such as the critical micelle concentration and the aggregate number of micelles, due to the hydrogen bonding between protonated and deprotonated species.