Self-assembly and micellization of amphiphilic rod–coil block oligomer at the mica–water interface

Abstract

In this paper, in situ atomic force microscopy has been used to investigate the micellization and self-assembling structure of an amphiphilic rod–coil block oligomer (EO 16OPV) containing a conjugated oligo(phenylene vinylene) dimer and poly(ethylene oxide) at the mica–water interface. It is found that EO 16OPV molecules have strong adsorption and aggregation properties on mica. In the wide concentration range from above the critical micelle concentration (cmc) to far below the cmc, a closely packed layer of stripe-like micelles with two preferred orientations can be formed at the mica–water interface. A cylindrical micelle structure for the stripes is proposed. We demonstrate that the stripe-like micelles formed on mica originate from different micellization processes at solution concentrations above and below the cmc. The origins of the strong micellization properties and oriented arrangement of the stripes are also discussed.