Functional Surfactants for Carbon Nanotubes: Effects of Design

Surfactants are needed to create stable suspensions of carbon nanotubes. Increasingly, these surfactants are given additional functionalities, resulting in bigger and more complex molecules with several subunits. We investigate the effect of assembly of these subunits for a class of perylene-based functional surfactants. The subunits that all surfactants are based on are a perylene core, hydrophilic polyglycerol dendrons, and alkyl chains of different orientations and lengths. The assembly of these subunits affects both the molecules performance as a surfactant and the efficiency of the energy-transfer complexes formed by the nanotube and surfactant through a pi-pi stacking mechanism. This results in a best practice guide for designing functional surfactants with pi-pi stacking cores, and affords more general insights that are applicable to non pi-pi stacking systems as well.