Self-Assembly of Carbon Nanotubes Modified by Amphiphilic Block Polymers in Selective Solvent

Block copolymers of polystyrene and poly(tert-butyl methyacrylate) were prepared by ATRP. Halogen atoms at the chain ends were transformed into azide groups to obtain -N(3) terminated block copolymers, which were connected to the surface of multi-walled carbon nanotubes (MWNTs) by reacting -N(3) with MWNT's surface. Amphiphilic diblock copolymer modified MWNTs were obtained after PtBMA blocks were hydrolyzed to poly-methyacrylic acid (PMAA). Results showed that the amphiphilic diblock copolymer was grafted onto MWNTs by covalent bonds. TEM showed that they formed self-assembly structures by hydrophilic/hydrophobic interaction in good solvents. As the block length of PMAA increased, the self-assembly structures of amphiphilic MWNTs became increasingly ordered and uniform.