Aqueous carbon-nanotube-amphiphilic-block-copolymer nanoensembles: Towards realization of charge-transfer processes with semiconductor quantum dots

The preparation of water soluble carbon nanotubes (CNT)-amphiphilic block polyelectrolyte nanohybrids for in situ synthesis of semiconducting CdS nanoparticles was analyzed. These nanohybrids are also used to evaluate the electronic interaction in CdS quantum dot-decorated CNTs. The block copolymers (PSHI) used in the process is a hydrophobic polystyrene block and a biocompatible heparin like polyelectrolyte, which is a sodium isoprene block. The protocol for the preparation of the CNT/PSHI nanohybrids involved codissolution of solid polymer and CNTs in water. Free polymer chains and insoluble nanoparticles and amorphous carbon were removed by centrifugation and filtration of the resulting inklike CNTs/PSHI solution. The protocol developed takes advantages from both steric hindrance between the amphiphilic block-copolymer-decorated tubes and the electrostatic repulsion between the polyelectrolyte chains.